Prison officials in Phangnga reported a man serving a sentence there had died from heatstroke while being punished under the hot sun, not from a severe beating as his family believed, the head of the Corrections Department said on Friday.
Kobkiat Kasiwiwat, the director-general, said the initial investigation report stated Suriya Suparak had a fight with another inmate at Takua Pa prison in Phangnga about 4am on April 1.
As punishment for fighting, the 47-year-old was ordered to repeatedly roll over on some sand outside under the sun. The hot sand had burned his skin and the fierce sunlight had further heated his body. The report said he died of heatstroke, Mr Kobkiat said.
The director-general acknowledged the argument from Suriya's family that he had a ruptured liver, broken ribs and other indications of a severe physical assault.
It was still too early to conclude the real cause of the death, Mr Kobkiat said. The department would await an official autopsy result and the questioning of eyewitnesses to the fight - how it happened and how long it had lasted.
On Thursday, the dead man's brother Weerayut Suparak complained that Suriya had many injuries to his body. An autopsy in Surat Thani province concluded Suriya had three broken ribs, a ruptured liver, swelling of the brain and bruises caused by being hit with a blunt object.
Suriya, a native of Nakhon Si Thammarat province, was arrested in Krabi province for drug abuse. Four years ago he was moved to Takua Pa Prison and was set to be released in another year, his brother said.
The family has postponed the cremation and is waiting for a fair investigation into his death.