A British woman and her boyfriend have been found dead in a Bangkok hotel room after unwittingly taking what they believed was cocaine but turned out to be a lethal mixture of nine different drugs.Rebecca Turner, 36, and her partner Sam, a self-employed gas engineer and plumber, were found dead on March 15 at the Khaosan Palace Hotel.The couple had purchased what they thought was cocaine from a street dealer in the Thai capital, but tests later revealed the powder contained a deadly combination of painkillers, sleeping pills and anxiety medications.Rebecca, who had previously lived in Laos for four years, was just one month away from returning home to the UK when the tragedy occurred.The couple had bought what they thought to be cocaineGettyCCTV footage showed Sam entering the hotel half an hour before his girlfriend on the day of their deaths, with phone records revealing he had texted a friend to say he had just bought cocaine.The couple are believed to have died around 1pm that day.Their bodies were discovered by friends who went looking for them after they failed to check out of the hotel.Sam was found lying in bed, while Rebecca’s body was discovered on the floor, with her mother saying she believed her daughter had tried to reach the bathroom.The pair had been in Thailand following a friend’s wedding in neighbouring Laos, where Rebecca had previously spent four years and considered her “second home”.Rebecca’s devastated mother Anita Turner, 64, from Bexhill-on-Sea, East Sussex, has issued an emotional warning to other young travellers about the dangers of buying drugs abroad.LATEST DEVELOPMENTS: The couple were found dead at the Khaosan Palace Hotel in BangkokGoogle Street View”My heart is just broken in two — I can’t believe I’ll never see her again,” she said.”Every morning I wake up and see a picture of her and just cry and cry. It’s killing me. The pain of losing a child is indescribable.”Anita emphasised the severe risks of purchasing drugs in Thailand, saying: “There is a massive drug problem out there and you just don’t know what you’re getting or how strong it is.”So many people are dying and people need to know about this. That road is particularly bad — a boy died of the same thing just a day before.”I just want to tap people on the shoulders and tell them: just please don’t take anything.”The pair had been in Thailand following a friend’s wedding in neighbouring LaosGettyOfficials revealed that toxicology tests found nine different substances in Rebecca’s system, including opiates, morphine, codeine, noscapine, benzodiazepine, temazepam, lorazepam, diazepam and monoacetylmorphine.Anita said she received an autopsy report from Thai authorities, but parts were censored.She said: “I’m sure they blacked out the bits where it said what drugs were in her body. They don’t want people to know how bad the problem is out there.”A UK inquest into Rebecca’s death is expected to be heard in January.The Foreign, Commonwealth and Development Office said: “We are supporting the family of a British national who died in Thailand and are in contact with the local authorities.”