Two people allegedly suffocated inside a sports utility vehicle parked, allegedly of asphyxia, at a petrol station in Bangkok's Bang Na area on Saturday morning.
Police went to the petrol station at Soi La Salle and found the Ford Escape with a Bangkok licence plate with its engine off and all windows closed.
A man, who was in the fully reclining drivers' seat, and a woman in the seat next to him, were found dead. There were no bruises on their bodies nor traces of a struggle, Thai media reported.
The driver was later identified as Saksit Bunnak 37, and the woman was Ms Prathueng Thong-ied, 52.
Police believed the pair died of asphyxia.
Staffers at the petrol station told police that the vehicle had been parked with the engine on in the early hours of Saturday. As they did not see anyone leave the vehicle, they came to check and knock on a car window several times, but the pair did not wake up.
Post Today reported that police managed to contact relatives of the dead people. They were investigating.