Mourners carry an effigy of Chea Vichea, the prominent trade union leader and opposition party supporter who was gunned down in an assassination on January 22.

P olice say they have the killers of union leader Chea Vichea, but in a dramatic press conference yesterday the two arrested suspects claimed the authorities beat them until they confessed.

Bourn Samnang (aka Bourn Sambath), 23, and Sok Samoeun, aka Boeun, 36, were led from police custody handcuffed and wearing black hoods before being paraded before news media.

"Bourn Samnang admitted that he was the man who shot Chea Vichea ...[and] Sok Samoeun is the partner of Bourn Samnang," said police chief Suon Chheang Ly yesterday afternoon.

Ly said police arrested Samnang on January 28 in Prey Veng province and Samoeun on the same day in Phnom Penh. He said both men were unemployed. Ly indicated that the K59 handgun sitting on the desk next to a revolver and around 15 bullets was the murder weapon.

"The killers got $1500 before the shooting and were promised another $3500 after [Vichea was] killed," said the police chief, adding that the man who hired them got away.

He said a trial would begin in two days.

However, the suspects denied they were responsible and cried as they protested their innocence to media.

"Police hurt me two times on the head and forced me to thumbprint," said Bourn Samnang, who police say was the gunman.

"I don't know anything, it is an injustice for me" said Sok Samoeun crying. "They cheated me. I've never known Bourn Saznang."

The arrests come a week after Chea Vichea, an outspoken workers' rights campaigner and supporter of the opposition Sam Rainsy Party, was gunned down as he read a newspaper near Wat Lanka in Phnom Penh. Two men escaped on a motorcycle. His killing was quickly branded politically motivated and human rights groups from around the world urged authorities to bring the assassins to justice.

The murder has caused fear among other leaders that they may be next.

On January 26 the SRP issued a "white list" of "Cambodia's public figures to be protected because they are allegedly on the CPP's Black List of persons to be assassinated in the near future." The list included Sam Rainsy, SRP secretary-general Eng Chhay Eang, Funcinpec secretary-general Norodom Sirivudh, director of the Cambodian Centre for Human Rights Kem Sokha and president of the Cambodia Independent Teachers Association Rong Chhun.

The statement was directed to the "Phnom Penh government... to warn them that they will be held responsible - with a personal responsibility for Mr Hun Sen - if any assassination attempt is effectively made on any one of the above possible targets."

In an interview with the BBC Sam Rainsy said, "I have suspicions that it is a politically motivated assassination and that the ruling party...is behind the assassinations."

Prime Minister Hun Sen responded strongly. Khieu Kanharith, spokesperson for the CPP said they were taking legal advice over the accusations.