They demanded that Lt-General Chalor Kerdthet, 69, be detained in an area away from other convicts.

"He's a former police officer. He has made a huge contribution to the country and sent so many offenders to jail. How can he and the others be locked up in the same area?" Pol Major Chaithawat Rittem, one of the visitors, said yesterday.

Chaithawat used to work under Chalor, who was involved in the notorious Saudi gems case.

Chalor was assigned to solve a high-profile case in which a Thai worker stole a large amount of jewellery from the palace of a Saudi Arabian prince in 1989.

Earlier this year, the former police chief was given the death penalty by the Appeals Court for orchestrating the abduction and premeditated murder in 1994 of a jeweller's wife and their only son. The jeweller was said to have known where the Saudi heritage pieces were hidden.

The victims were killed despite payment of Bt2.5 million in ransom.

Chalor is detained at Klong Prem Central Prison pending his appeal to the Supreme Court.

He was injured during a clash between other inmates last week. One inmate was seriously injured in the brawl and needed up to 60 stitches.

Chaithawat, who now works for the Scientific Crime Detection Division, said yesterday that Chalor appeared to stagger and had bandages around both of his legs.

"He was reluctant to speak when I asked him how he was injured. Wardens were present during our conversation," Chaithawat said.

The police officer was also unhappy that the brawling inmates received visits from relatives at the same time and in the same area as Chalor.

Chaithawat said Chalor's wife Michel Kerdthet had assigned Jongkon Leelawong to submit a petition to Corrections Department chief Nathee Jitsawang on her behalf.

The petition asks that Chalor be sent out of the prison to receive a check-up and that he be detained separately from other prisoners.

"The petition also asks for information on what actions the Corrections Department has

taken against the brawling inmates," he said.