Sasom Watthanakool, 52, said six officers belonging to a unit of Muang police station apprehended him at a shrimp farm on the night of November 23 and planted a large number of amphetamine pills on him.

He said the unidentified officers later beat him up to force him to sign a confession stating that he killed his friend Somphob Hiranraksa.

Somphob had earlier been abducted from in front of the provincial prison along with his girlfriend and driven away in a vehicle. He was later found dead while his girlfriend, an unidentified woman, remains missing.

Sasom said the officers broke his three ribs, one of which pierced a lung. He was released from detention after eight days of daily assaults because his condition became serious. The officers released him to a local hospital, where he underwent an operation.

Sasom said he had earlier given two tablets to a friend, whose wife told him was critically in need of amphetamines. He claimed that he later found out that the officers had told the woman to call him up and say that the tablets were needed to prevent her husband from dying.

Sasom said he believed that the anti-drug police wanted to take revenge after he recently took Somphob's father to lodge a complaint about the kidnapping of Somphob and his girlfriend with provincial governor Anont Phro-menart and a senior police officer.

Provincial police chief Pol Maj-General Boworn Nanthayawong said he thought Sasom's story was not credible and that police had not yet found or arrested Somphob and his girlfriend's abductors.