KALASIN: A police officer was found stabbed to death, his body mutilated, in Kamalasai district of this northeastern province early on Monday.
Police later arrested Amornlak Jitkoh, 45, a Kalasin native, who fled and hid in a forest in Nakhon Ratchasima's Sida district.
He was tracked down, persuaded to surrender and returned to Kalasin.
Investigators said the man's wife had an affair with the victim.
Police, medical staff from Kamalasai Hospital and a rescue unit rushed to Ban Noi Pattana in tambon Kamalasai about 1.30am after the body's discovery was reported.
In a wooden house under construction, the body of a man, wearing a black T-shirt and yellow-black shorts, was found lying face up in a pool of blood. He had been stabbed at least 20 times - on his torso, buttocks and thighs. His genital organs were cut off.
The man was later identified as Pol Lt Col Jamras Dolchua, 57, of Rong Kham police station in Rong Kham district.
Piles of leaves and other inflammable material had been set on fire at many spots around the house. A fire was also set at the rear of a white Toyota Fortuner parked there. The fires had been put out by neighbours. There were scorch marks on the rear of the vehicle.
Police found three beer cans in front of the house.
A son of Pol Lt Col Jamras told the police that his father usually stayed overnight at a house in Kalasin town. He occasionally spent the night at the wooden house at Ban Noi Pattana in Kamalasai district.
His father formerly had an affair with a woman who told him she was a divorcee. He later stopped their relationship after learning that the woman was not divorced.
The son, who was not named, believed the woman wanted to return to his father, upsetting her husband. This could be a motive for murder, he said.
The body was taken to Khon Kaen Hospital for an autopsy.
The fire-blackened rear of the Toyota Fortuner at the scene of the murder of a senior police officer in Kalasin (Photo by Yongyuth Phuphuangpet)