PICTURED: California couple who died in their Mexico hotel room

The American couple who died in their Mexico hotel room were killed in their sleep by carbon monoxide poisoning, according to their families.  be pictured for the firs time 

Abby Lutz, 28, and John Heathco, 40, were found unresponsive in their hotel room  at the five star, $780-a-night Hotel Rancho Pescadero near Cabo San Lucas on Tuesday. 

Abby worked as a nanny while John ran a health supplements website. 

According to Abby's family, who are now raising money to bring her home, they died as the result of carbon monoxide poisoning. 

Abby Lutz, 28, and John Heathco, 40, were found unresponsive in their hotel room on Tuesday 

The couple was staying at the $780-a-night Rancho Pescadero hotel in El Pescadero, near Cabo San Lucas

'While on a beautiful trip in Mexico, Abby and her boyfriend thought they had food poisoning and went to the hospital to get treatment.

'We were told they were feeling much better a few days later. We received a phone call saying that they had passed away peacefully in their hotel room in their sleep. 

'We have been told it was due to improper venting of the resort and could be Carbon monoxide poisoning,' a GoFundMe page set up by the family says. 

Representatives for the hotel, which is owned by American company Hyatt, has not responded to the claim that carbon monoxide could be to blame for the couple's deaths. 

Abby's family is now raising money to bring her remains home and pay for her funeral 

Abby, 28, with her younger brother, who paid tribute to her on Thursday 

Abby worked as a nanny in Newport Beach, California

An autopsy is yet to confirm how they died but police say it was due to suspected gas inhalation. 

It's unclear how long the pair had been dating or how long they were scheduled to be in Mexico. 

There have been several other instances of tourists dying in hotel rooms due to carbon monoxide poisoning. 

In June last year, a Florida couple died while on vacation at a Sandals Resort in the Bahamas. 

In November, three other tourists died while staying in a rented apartment in Mexico City. Their cause of death was carbon monoxide poisoning. 

While Hyatt has not yet responded to the claim regarding the ventilation and how it could have caused their deaths, the hotel's general manager said they were 'heartbroken'. 

'We are truly heartbroken by this terrible tragedy. 

'Our hearts are with the impacted families and loved ones during this unimaginable loss,' she said.  

The couple was found in their hotel room at the Hotel Rancho Pescadero on Tuesday