Cyanide found in blood and teacups of six dead in Bangkok

Investigators believe six Vietnamese and American guests who died at a luxury hotel in Bangkok were poisoned by cyanide after an initial autopsy revealed traces of the poison, Thai authorities said on Wednesday.

In a press conference on Wednesday, Lt. Gen. Thiti Sangsawang of the Bangkok police identified two Americans with dual citizenship among the three Vietnamese killed. Police said they were between 37 and 56 years old.

Thai Prime Minister Srettha Thavisin said the U.S. and Vietnamese embassies had been contacted about the deaths and the FBI was en route to investigate, according to the Associated Press.

The bodies were found by a chambermaid on Tuesday when the guests failed to check out. The room door at Bangkok’s Grand Hyatt Erawan was locked from the inside. Police, who found traces of cyanide in the tourists’ teacups, a teapot and the blood of one of the dead, said there were no signs of a struggle. A full autopsy report is expected on Thursday.

Police interviews revealed that four of the six victims had invested money together and that there may have been disputes over debts related to the investment. Noppasin Punsawat, Bangkok’s deputy police chief, told a press conference that the investment was for the construction of a hospital in Japan.

Given the personal nature of the situation, Noppasin said the case was unlikely to impact a conference with Russian Energy Minister Sergei Tsivilev scheduled to take place at the hotel later on Wednesday. “This was not an act of terrorism, nor was it a security breach. Everything is fine,” he said.

The men and women were last seen alive on Monday afternoon when staff brought food and drinks into the room. Video footage then showed the six entering the room before closing the door for the final time.

Lt. Gen. Trairong Piwpan, chief of the Thai police’s forensic department, said police had ruled out a mass suicide because members of the group had arranged activities with guides and drivers. He added that the six bodies were found in different parts of the room, meaning it was unlikely they had deliberately ingested the poison and waited to die.

In 2023, a serial killer in Thailand named Sararat Rangsiwuthaporn, also known as “Am Cyanide,” was charged with poisoning 15 people over several years with the deadly chemical, which interferes with the body’s ability to absorb oxygen. She killed at least 14 people to whom she owed money, with one person surviving, the Associated Press reported. She was the country’s worst serial killer and the first female.