It was early on Tuesday morning when the bodies were found at a luxury hotel in central Bangkok.
According to the local police, it is likely a poisoning.
Local media writes that five of the bodies were found in a hotel room, and a sixth body was discovered outside the room.
The deceased hotel guests are said to be of Vietnamese origin.
The incident prompted Thailand's Prime Minister Srettha Thavisin to visit the site, where a large media gathering had assembled during the evening.
