A witness has told the trial of former Yugoslav leader Slobodan Milosevic that he had served in a paramilitary group allegedly controlled by the former president.

The witness, called "K-2" to protect his identity, told the tribunal he had served in the Special Operations Unit which was part of Serbia's secret service during the 1992-95 war in Bosnia and was operated under the direct command of Mr Milosevic's regime.

Arkan was shot dead in January 2000

Also known as the Red Berets, the hardline nationalist Serb group was notorious for its brutality in fighting in Croatia, Bosnia and Kosovo and was recognised by its trademark black army fatigues and red caps.

After the war, it became the anti-terrorist unit of the Serbian Interior Ministry. In 2000, it helped to overthrow Mr Milosevic from power.

"We had full support in the form of ammunition, uniforms, and all other necessities," said the witness, whose image was blurred on court monitors.

Pay slips or cash wages came in envelopes from the Serbian Interior Ministry, he said, and Mr Milosevic had been the man in charge.

"Our unit had to do whatever it was asked to do. There was no possibility to say no... The doors of the president were open to us," he said.

Asked which president he meant, he replied "as far as I was able to gather, there was only one president and that was President Milosevic".

Arkan killing

During cross examination by Mr Milosevic, who is conducting his own defence, K-2 acknowledged his involvement in the 2000 killing of the Yugoslav warlord Zeljko Raznatovic, better known as Arkan.

"That is the main reason why you are no longer living in Serbia and concealing your identity?" Milosevic said.

"Yes," the witness answered.

K-2 declined to answer Mr Milosevic's questions about his current occupation and residence in open court session, and hearings were briefly closed to the public.

The trial, which had been suspended because of Mr Milosevic's poor health, resumed in The Hague after a three-week break.

The trial has already been interrupted several times last year, but the judges rejected a prosecution request to assign a lawyer to help Mr Milosevic with his defence.

The prosecution has until May to wrap up its case against the former president.