The bodies of the couple were discovered at 5pm tonight at the Baantonsai Garden Resort when a maid used a spare key to open the door.
Inside the room, the naked body of Yuwandee Srikeat, 29, lay on a bed. She had been strangled, police later determined.
Hanging from the curtain rod was Prasit Intaro, an elected councillor from Trang province who also drove a ''black'' illegal taxi in Patong.
The couple checked in to the resort at 12.45am today, police learned.
They paid 320 baht and a refundable deposit and were due to check out in the afternoon.
At 5pm, the maid received no response to her knock so opened the door to discover the two bodies inside the room.
Paramedics believe the couple could have been dead for about five hours.
Police found a note written by Khun Prasit apologising for what had happened to his family and to the child he fathered.
He left his wife for Khun Yuwandee.
Patong police are investigating in the belief that Khun Prasit killed Khun Yuwandee then himself when he discovered that she was having an affair with an Australian man.
Khun Yawandee worked at the Smile Inn at Patong Tower.