A British man found dead in a hotel room in Muang district of Chiang Mai province early yesterday was believed to have died using a helium suicide mask.
Pol Capt Montree Putthakhan of Muang district police said investigators, medical staff from Maharat Nakhon Chiang Mai Hospital and rescuers were dispatched to the hotel on Wiang Ping road in tambon Chang Khlan about 1am.
Earlier, an employee reported a foul smell coming from a room.
Inside the room they found a British man, identified as Stephen Malcolm Roston, 62, lying dead on the bed.
His mouth was covered with a plastic mask connected by a tube to a helium tank by his bedside. Another tank of helium was also found in the room.
The doctors said the man died about three days earlier.
His belongings were left untouched.
Police also found a suicide note, which indicated Roston intended to end his life by inhaling helium while listening to songs from his computer.
When the rescuers found him, his laptop was on playing music.
Roston had stayed in the hotel room for about seven months, police said.
According to his hotel registration documents, Roston was a British national and former architect.
Police believe he committed suicide.
Several other foreigners had also killed themselves using this method, police said.