A BARTENDER has been arrested in Vietnam after allegedly making the deadly cocktail that killed a British tourist and her fiance.

The bodies of 33-year-old Greta Otteson and her South African fiance Arno Els, 36, were found in their Vietnamese villa after they drank toxic limoncello.

The couple died from methanol poisoning over Christmas and were found in their Hoi An villa on Boxing Day.

Local bartender Le Tan Gia, 45, was arrested on Friday on suspicion of making the toxic drink that led to their deaths, state media has said.

Officers claimed Gia had used 70-percent medical alcohol, mixing it with water, lemonade and sugar to make bottles of limoncello on December 24.

“After taking the drinks, the two suffered serious methanol poisoning, leading to their death,” the report said.

A police spokesman said: “The Criminal Investigation Police Department of Quang Nam Province has arrested Le Tan Gia, of Cam Nam Ward, Hoi An, on charges of violating food safety regulations.

“The prosecution of the defendant will continue, based on the evidence that he served the victims methanol drinks that caused their deaths.

“Currently, the case is being investigated and handled by the police force in accordance with the law.”

The newly engaged couple had been given the two bottles at a restaurant around 3:30 pm.

A source close to the family told The Times: “Police forensics established the limoncello, which had been delivered, was the source.”

The next morning, Greta messaged her parents, describing “the worst hangover ever” and seeing “black spots” in her vision.

Despite these alarming symptoms, the couple decided to sleep it off.

A concerned local bar owner offered to take them to the hospital, but they declined.

They were discovered on Boxing Day by horrified resort staff.

Greta was found lifeless in her bed, while Arno was discovered dead in a separate locked room.

A Quang Nam Provincial Police spokesman said: “There were no signs of ransacking at the scene.

“The victims’ belongings and phones were untouched.”

Police added that there were no signs of scratches or physical trauma on the bodies.

As part of the investigation they confiscated several used bottles of alcohol from the crime scene.

The pair had been staying at the villa for a number of months after arriving in early July.

Police have confirmed that the investigation into their deaths is still ongoing.

Greta’s devastated parents, Susan and Paul, said in a statement: “Greta and Arno were experienced worldwide travellers.

“They found their perfect home and were incredibly happy.”

Paul, originally from Swansea, shared a photo of the couple smiling at each other during their engagement photoshoot and described Arno as “a lovely boy…a great musician, composer, and lyricist.”

Their deaths came just five weeks after six tourists died from suspected methanol poisoning after a night out in the Laos backpacker hotspot of Vang Vieng.

The tourists, including British lawyer Simone White, 28, died after drinking contaminated vodka shots at a hostel.

Eight staff members have also been arrested after reportedly refusing to call an ambulance for the dying guests.

Among the victims were Danish friends Anne-Sofie Orkild Coyman, 20, and Freja Vennervald, 21, who died after they were left “vomiting blood” for 13 hours.