Mysterious unsolved case of former Penthouse 'Pet of the Year' whose body washed up in a restricted area of a Marine Corps base with a broken neck and back

An upcoming true crime series is set to delve into the mysterious death of a former Penthouse 'Pet of the Year' whose body was found washed up in a restricted area of a Marine Corps base with a broken neck.

Anneka Vasta, who was born Marjorie Lee Thoreson, lived a life of relative glamour in the 1970s and 80s.

She shot to fame after being named the 1975 Penthouse Pet of the Year, under the name Anneka Di Lorenzo, and later appeared in Bob Guccione's infamous soft-porn film Caligula.

But, in January 2011, two joggers found the 58-year-old's naked body in a restricted area on a Marine training beach at Camp Pendleton in San Diego County, California.

Here, FEMAIL has laid bare the sordid details as an episode of Lethally Blonde gets set to unravel the case.

An upcoming true crime series is set to delve into the mysterious case of former Penthouse 'Pet of the Year' Anneka Vasta

In January 2011, two joggers found the 58-year-old's naked body in a restricted area on a Marine training beach (pictured) at Camp Pendleton in San Diego County

Anneka, who was born in St. Paul, Minnesota, had been on a rocky road from the beginning.

She dropped out of high school and moved to Los Angeles - after her parents divorced in 1965 - where she worked as a receptionist, cocktail waitress, and topless dancer.

She met photographer and publisher Bob Guccione, who founded the adult magazine Penthouse, in 1973.

The businessman quickly agreed to make her the Pet of the Month for that September - flying her to New York, and then to London for photoshoots that would thrust her into the limelight.

The magazine publisher also got her the role of Roman empress Messalina in Caligula.

And Anneka, then going by the surname Di Lorenzo, was quoted at the time as saying: 'How famous do I want to be? 

'Let's just say that I'm going to be the sexiest woman in the world.'

But it turned out not to be so straightforward. 

The star (left) had been named the 1975 Penthouse Pet of the Year, under the name Anneka Di Lorenzo, and appeared in Bob Guccione's infamous soft-porn film Caligula (right)

Anneka (pictured alongside Swiss artist H.R. Giger), who was born Marjorie Lee Thoreson, lived a life of relative glamour in the 1970s and 80s

Her career suffered from the backlash over the 1979 feature film which was the first major movie to feature eminent actors, including Helen Mirren, in explicit sex scenes.

Anneka's onscreen career soon fizzled out and her final role was a small part as a nurse in Brian De Palma's Dressed to Kill.

Things only got worse when she sued Guccione in 1988 on charges of sexual harassment and he was found guilty of compelling her to have sex with two business associates.

Despite being awarded the groundbreaking damages of $4 million, Anneka only won a measly $4.06 after an appeal ruled money was not recoverable and vacated the award.

Guccione, who died aged 79 in 2010, struck back at her by reprinting photos of Anneka's lesbians love scene from Caligula with Lori Wagner in the February 1991 issue of Penthouse.

Anneka sued Bob Guccione in 1988 on charges of sexual harassment and he was found guilty of compelling her to have sex with two business associates

Anneka, who was divorced and in and out of jobs at the time of her death, had been living near her sister, Susan Thoreson, in Sherman Oaks, Los Angeles.

Susan said the actress, who had a daughter, had begun showing signs of mental problems about six or eight years prior - suffering bouts of paranoia and anxiety, according to the San Diego Union-Tribune.

The former Penthouse model is believed to have left Los Angeles in the early hours of January 2, 2011, and driven south in a maroon Mazda with many of her possessions packed in the trunk, the paper said. 

Just before 6 a.m., she rented a room at a Motel 6 - but would never check out.

She drove around until 8.30 a.m., making calls to family and friends, the last of which was from the vicinity of where she parked her car - which was found at a popular scenic overlook along Interstate 5.

Anneka's death remains shrouded in mystery despite there being no explicit evidence of foul play

But what happened after that is a mystery with authorities struggling to determine how Anneka got from the vantage point 60ft above sea level, to the rocky sand below, more than a mile south.

Her body was found by two joggers after it was washed up on the military training beach. 

It was determined that Anneka, who had suffered from a broken neck and back, had drowned.

When investigators discovered the Mazda, her phone and purse were still in it, as well as a blood-stained leopard-print blouse and a sports bra, which was wrapped in a plastic bag from the Motel 6.

A steak knife with Anneka's blood on it was found by the passenger footwell.

Lithium and an empty bottle of Xanax were found in the car but an autopsy showed no drugs in the dead woman's body.

The medical examiner reported shallow cuts on Anneka's wrists, consistent with a half-hearted suicide attempt.

She also had two stab wounds on her chest, the San Diego Union-Tribune reported at the time.

But Anneka's three sisters maintained that she would not have taken her own life, and were troubled by the fact her neck and back were broken while she was still alive.

Her family believe the star's open nature could have led her into trouble.

'She's like a little girl out in the street. A stranger could walk by, and she'll pick up a conversation with them,' Susan told the San Diego Union-Tribune.

Anneka's death remains shrouded in mystery despite there being no explicit evidence of foul play.

The Lethally Blonde series premieres on Investigation Discovery on March 25