Held down and forced to swallow Novichok... That's the most likely explanation for the death of the heroic Alexei Navalny, concludes DAVID JONES following a forensic investigation that suggests Putin's goons were at the scene of the crime

During the depths of winter, just a handful of flights land each day at Salekhard airport, inside the Russian Arctic Circle.

As temperatures plunge below -30c and semi-permanent darkness shrouds the bleak tundra landscape, few outsiders willingly venture there. Among them are oligarchs, who make the three-hour trip from Moscow on private jets to hunt for reindeer and wolverine.

Unwilling arrivals are brought by cattle-class train, a journey that takes 45 hours, and decanted at FKU IK-3, otherwise known as Polar Wolf, a nightmarish penal colony whose razor-wired walls scar the snowscape, 35 miles away across the frozen Ob River.

At around 6pm last Saturday, local taxi drivers raced to the airport after being tipped off that an unscheduled jet had just touched down. It was followed by a second unexpected plane, carrying at least eight people, some 90 minutes later.

But if the cabbies hoped to boost their meagre incomes with fares into the city, they were to be disappointed.

For according to one driver, Andrei, the passengers on these unannounced flights were escorted through the airport's modern terminal, with its purple lighting, to a fleet of waiting cars belonging to the Investigative Committee — the Kremlin's fearsome law enforcement agency.

Alexei Navalny embracing his wife Yulia Navalnaya, who may be next on Putin's target list

Navalny's death was clearly timed to remind the West of Putin's ruthlessness and expunge a rival ahead of next month's rigged 'election'

Flowers placed around portraits of the late Russian opposition leader

A man holds a picture of the late Alexei Navalny reading 'A real hero of Russia'

Yulia Navalnaya remained loyal to her convicted husband to the end

Navalny with wife Yulia after being released by a court in July 2013. He received several jail sentences in his life

Navalny and his wife surrounded by journalists on the outskirts of Moscow in 2011

Mourners in Zagreb, Croatia, light candles in tribute to the Putin critic and challenger, who died in a Russian prison

Putin loathed Navalny so much that he refused to mention him by name, only referring to 'the Convict'

Who were these shadowy figures, and what had brought them to this grim outpost?

The timing and furtive nature of their visit suggests they were agents of the FSB, Russia's state security service, on a top-secret mission: to take charge of the body of opposition leader Alexei Navalny, who had been murdered in Polar Wolf a matter of hours earlier, and to ensure no one will ever find out who killed him, nor how he was dispatched.

So, what is the truth behind this blatantly Putin-sanctioned assassination? Why are the dictator's stone-hearted lackeys blackmailing Navalny's 69-year-old mother, Lyudmila, by refusing to release his body — in breach of Russian law — unless she agrees to a secret burial without a funeral service?

This week, theories on how and why he was killed have come thick and fast. Some more plausible than others.

However, by examining small scraps of information emerging in Russia, including the accounts of local witnesses to key events that occurred immediately before and after the murder, I have pieced together the most likely scenario.

It was an act clearly timed to remind the West of Putin's ruthlessness as, two years on from the invasion, the Ukraine war enters a crucial phase, but also to expunge the one rival capable of marring the celebrations of the president's certain victory at next month's rigged 'general election' — even from an Arctic prison cell.

But it was motivated, too, by Putin's thirst for revenge against the man who had exposed his corruption and sleaziness, revealing how he creamed off billions and built a 180-acre palace by the Black Sea.

Indeed, the remorseless brutality of Navalny's murder only becomes comprehensible when we grasp how deeply Putin hated him.

So visceral, so personal was this loathing that the Russian president refused even to hear or speak Navalny's name, referring to him as 'The Convict'.

Then, having had him jailed on risible charges of 'extremism', Putin decreed that every minute of his 19-year sentence must be made a waking hell.

Not content with consigning him repeatedly to solitary confinement in box-like punishment cells for the slightest infraction, such as leaving a shirt button undone, he psychologically tortured Navalny by circulating spurious claims that his wife Yulia, with whom he had two children, was cheating on him while he was in prison.

Just days before his murder, a young woman went online to claim she had resigned from Navalny's political organisation in disgust after witnessing these 'affairs'. Close inspection of this supposed whistleblower reveals her to be a digitally created avatar.

That Yulia remained unswervingly loyal to her husband and loved him with a passion until he breathed his last was evident from her public addresses this week.

That Putin had failed in his crude attempts to destroy his nemesis mentally as well as physically was equally evident when Navalny was last seen — making a court appearance by video link from Polar Wolf on Thursday, February 15, a few hours before he died.

A trained lawyer, he would deliberately engineer these hearings, using them to show supporters he remained unbroken and to mock the authorities. Last week, he was legally challenging his latest punishment, being denied the use of a pen and paper — his only means of communicating with the outside world.

With a trademark laugh, he told the judge he had been fined in prison so often that he was broke, and impishly implored him to spare him a few roubles from his 'huge federal judge's salary'.

When Navalny offered to send him his bank account details, even the court officials had to smile at his chutzpah.

The remorseless brutality of Navalny's murder only becomes comprehensible when we grasp how deeply Putin hated him

Navalny's 69-year-old mother, Lyudmila Navalnaya

That Yulia remained unswervingly loyal to her husband and loved him with a passion until he breathed his last was evident from her public addresses this week

Navalny and Yulia wait in raincoats at the start of a rally in Moscow in September 2013

Yulia lying down with her and Navalny's daughter Dasha Navalnaya

With his crewcut and baggy, black prison uniform, he certainly looked gaunt when making that valedictory show of defiance. Yet there was no sign of the ailments that weakened him after surviving Putin's poisoning attempt in 2020, such as numbness in his limbs and stomach pains. Given his dire regimen, he looked remarkably well.

All of which casts doubt on two of the theories circulating this week. Either that he died after being systematically poisoned over many months with a substance mixed into his prison meals, or that he had succumbed to years of maltreatment and undernourishment, perhaps exacerbated by a sadistic form of punishment practised at Polar Wolf: being forced to stand outside for hours in deep-freeze temperatures, wearing only a flimsy shirt.

We can surely discount, too, the Kremlin's lame — and ludicrously hasty — explanation.

Just two minutes after his official time of death, 4.17pm in Salekhard (2.17pm in Moscow) the prison service issued a suspiciously well-prepared statement, saying 'the convict' had 'felt unwell' during a walk and 'collapsed almost immediately'.

Valiant attempts had been made to resuscitate him (of course). To no avail. A few minutes later, state-controlled TV claimed he had suffered a blood clot or thrombosis. The speed with which they reached this diagnosis would have made Stalin blush.

So, too, the cabbage soup claptrap now being spouted by some of Putin's cronies: that Navalny's death couldn't have come at a worse time for 'the Boss', and that he was killed by a CIA hitman smuggled into the penal colony.

How, then, was this awesomely brave man — who knew he was probably signing his own death warrant when he returned to Russia after surviving that first poisoning attempt — really murdered?

The one genuine conundrum is over the Kremlin's methodology.

According to Vladimir Osechkin, exiled founder of the human rights group Gulagu.net, he is unlikely to have been killed by the nerve agent Novichok, the usual cause of 'Russian Sudden Death Syndrome' (to coin the macabre new terminology).

Instead, he suggests, Navalny was probably killed by one powerful, well-aimed blow delivered to his heart.

Basing his assertion on information from a source inside Polar Wolf, and bruises reportedly found on Navalny's body, Osechkin told The Times that this 'one punch technique' was perfected by the KGB, forerunner of the FSB.

'I think they first destroyed his body by keeping him out in the cold for a long time and slowing his blood circulation. And then it becomes very easy to kill someone within seconds, if the operative has some experience of this,' he said.

However, others, with first-hand dealings with Putin's murder machine, do not share this view. Navalny, they say, was probably poisoned again with the Novichok — this time more efficiently than in 2020, when an FSB agent unwittingly confessed to smearing it in the crotch of Navalny's underpants before he boarded a flight.

'The Russians tend to be very uncreative in how they go about all these assassinations,' says Bill Browder, the financier and political activist whose tax adviser and friend Sergei Magnitsky was murdered in a Moscow prison in 2009, after exposing wide-scale government corruption.

'They have a playbook that they've been using for 50 or 100 years,' he told me. 'There is something called the KGB poison factory where they come up with the technology. They use Novichok and five or six other poisons, and rarely deviate from the same techniques. They have people who do this. It's like an assembly line.'

Chemical weapons expert Hamish de Bretton-Gordon, a former commander of Britain's Joint Chemical, Biological and Nuclear Regiment, told me the 'single punch' scenario is the stuff of Hollywood spy movies.

The bruises suggest Navalny was held down and forced to swallow Novichok, says de Bretton-Gordon, who advised the government after the Salisbury poisonings of the defected former Russian agent Sergei Skripal and his daughter Yulia.

Whereas absorption through the skin can take hours or days to cause death, one drop on the tongue would kill within seconds.

Just a handful of laboratories in the world are sufficiently equipped to detect Novichok, and in Russia there is only one — the FSB lab where this elusive poison is made. 'And I don't think they are likely to find anything there,' de Bretton-Gordon added, sardonically.

Assuming he and Browder are right, the murder plan — which informed Russia-watchers say could only have been made on Putin's orders — would have been many weeks or months in the making.

Navalny with his wife Yulia at an opposition rally outside the Kremlin in June 2013

A woman lays floral tributes to Navalny at the Solovetsky Stone in Moscow

Navalny's widow Yulia with US President Joe Biden 

A tribute to Navalny outside the Russian embassy in Washington DC reads 'They could kill you, but they couldn't defeat you'

Another poster reads 'Alexei Navalny was murdered'. Some experts believe the former opposition leader was most likely poisoned with novichok

But it gathered pace on December 6, when Navalny mysteriously failed to appear via video at a court hearing and lost contact with his aides.

His 1,200-mile transfer, from a prison within driving distance of Moscow to one of the world's most brutal and unreachable penal colonies, only became known on Boxing Day, when he filmed a jovial message smuggled out by his lawyer.

Such was the secrecy surrounding his journey, he revealed, that he had been smuggled from city to city and travelled for 20 days before reaching Polar Wolf. Making light of conditions that have subjugated Russia's toughest criminals, he jokingly portrayed himself as Russia's 'new Santa Claus'.

Yet Browder believes his fate was sealed even then. 'I suspect they moved him to the Arctic because they knew there would be a lot of attention after [the murder] and wanted him as far away as possible from civilisation,' he told me.

Refusing to address warders correctly, attempting to form a union for prison labourers, and rebelling at every opportunity, Navalny spent much of January in a cramped punishment cell with a hole in the floor for a toilet, a pull-down bed, and a tiny window through which he could see only a fence.

However, when his mother visited him, on Monday, February 12, and they chatted through a reinforced glass partition, she says he was 'alive, healthy, cheerful'. A lawyer who met him two days later was similarly encouraged by his demeanour.

His apparent high spirits during two videoed court appearances on Thursday provided further reassurance. Yet behind the scenes, final preparations for his removal were doubtless well under way.

According to security experts, the killers would have been flown in from Moscow and smuggled into Polar Wolf.

Though their plans were clearly well-rehearsed, the plot was marred by errors which give Navalny's supporters some hope of exposing the killers and proving beyond doubt Putin's culpability.

Firstly, the jumpiness of the wardens on Thursday evening made it obvious to inmates that something momentous was about to happen in the prison, if it hadn't already.

There was a rush to complete the evening headcount, then prisoners were locked in their barracks and security was so tight 'you couldn't even stick your nose out' of your cell, one inmate told the independent Russian news outlet Novoya Gazeta Europe.

Unusually, he heard the crunch of tyres on ice on three separate occasions later that night, as cars went in and out of the camp. The strange events continued the following morning. Personal items such as mobile phones and the portable devices prisoners use to boil water were confiscated, leading them to suspect an imminent high-level inspection. This belief was furthered by the governor's panic-stricken expression.

Though Navalny's death was announced that Friday afternoon, it all suggests that he had been murdered much earlier, possibly on the previous day, and that the authorities were playing for time as they attempted to cover the killers' tracks and dispose of his body. A Moscow journalist claims she learned of his death at noon, local time, more than two hours before the official statement was released.

Meanwhile, in the industrial city of Chelyabinsk, where he was touring a factory, Putin made sure to appear before the TV cameras, his mask-like features etched with a self-satisfied smirk.

His smile might have dimmed somewhat on Friday night. For then came the clumsiest mistake of the operation. While the orchestrators had gone to great lengths to ensure the murder couldn't be filmed, removing inmates' phones and disconnecting the Polar Wolf security monitors, someone forgot to switch off the CCTV cameras lining the 35-mile highway between the penal colony and the city of Salekhard.

Though the Putin regime is repressive in many ways, the Russian public can view this footage with a simple Google search and, as enterprising reporters sifted through it, they made a crucial discovery.

Alexei Navalny appears via a video link from the Arctic penal colony in Kharp

Putin's vindictiveness knows no limits, and Navalny's widow Yulia could be next in his sights

Either side of midnight on Friday, a convoy of federal penitentiary vehicles could be seen heading away from the penal colony, along the deserted road. Flanked by what appeared to be escort cars, it included a Soviet-designed prison van, nicknamed a 'bread loaf', which has a caged rear compartment big enough for a stretcher.

It is believed this van had just collected Navalny's body and was delivering it to a mortuary — though not the one to which his forlorn mother was directed when she returned, hoping to see her son for the final time and take him home to be buried.

Assuming this to be correct, it might explain the unexpected arrival of the two planes seen by taxi drivers on Saturday evening.

Were they carrying FBS officers deployed to guard his body, and government scientists tasked with testing and retesting it until every last clue to the presence of Novichok had disappeared beyond trace?

We cannot know for sure, of course. But given that his mother was made to wait for several days before being taken to a mortuary to see him this week, and that officials last night were threatening to bury him in the penal colony uness she agreed to a secret funeral within three hours, it seems distinctly likely. 

Last night, this grieving woman — who has reluctantly signed a death certificate stating that her son died of 'natural causes' — was faced with an agonising dilemma. Should she comply with the ultimatum, depriving a great Russian champion of freedom a fitting send-off, or leave him in limbo? As one official told her callously: 'Time is not on your side, the corpse is decomposing.'

So, the question remains. How was he really killed? Over the coming days, Navalny's inner circle will strive to uncover the full story. But no one I have spoken to this week expects them to succeed.

As with every 'sudden' Russian death, the only certainties are that we will never learn the unexpurgated truth, and that there will be many more victims.

For Putin's vindictiveness knows no limits. And chillingly, having nobly pledged to take up her husband's mantle, Yulia Navalnaya may be next in his murderous sights.

• Additional reporting by Russia specialist Will Stewart and Tim Stewart in London