Cyanide poisoning likely killed six found dead in luxury hotel, including two US citizens, Thai police say

Bangkok, Thailand CNN —

Six people, including two US citizens, who were found dead inside a luxury hotel room in central Bangkok likely drank from tea and coffee cups laced with cyanide following a dispute linked to bad investments, Thai police said Wednesday.

The grisly discovery was made on Tuesday when staff at the five-star Grand Hyatt Erawan in the Thai capital entered the fifth-floor suite after the guests missed check out by more than 24 hours.

When police arrived at the scene, they found the bodies of three men and three women, a table full of untouched food wrapped in plastic and used cups with traces of a white powder. The door was locked from the inside, police said, though a backdoor was left unlocked.

Authorities initially said they were searching for a seventh person who was part of the hotel booking. But on Wednesday they dismissed this line of inquiry, saying they believe one of the deceased poisoned the others with the deadly fast-acting chemical cyanide.

Among the dead are two Vietnamese Americans and four Vietnamese nationals including a married couple aged between 37 and 56, Thai police said.

Chief of the Police Forensic Office Trairong Phiewphan said in a press conference that cyanide was found in mugs and cups in the hotel room and at least one of the blood samples collected from a deceased man had traces of the chemical.

“Cyanide was found in the liquid inside the teapot, in all six coffee cups,” Trairong said.

Uneaten meals are left on a table in a suite at Bangkok's Grand Hyatt Erawan Hotel, where six people were found dead on July 16, 2024.

Images issued by the Royal Thai Police showed cups on a coffee table next to two metal thermos flasks and a dining table laden with plates of food,