The former second-in-command of Cambodia's Khmer Rouge regime has been arrested and is being held in a specially-built prison outside Phnom Penh. Noun Chea is only the second senior leader of the Khmer Rouge to be arrested for his part in the deaths of almost two million people in Cambodia in the late 1970s. Rory Byrne reports for VOA from Phnom Penh.

Former Khmer Rouge number two leader Nuon Chea, top, boards helicopter in Pailin, 19 Sep 2007

Police arrested Noun Chea at his home on the Thai-Cambodian border in the early hours of Wednesday morning.

He was taken by helicopter to a prison outside the capital, Phnom Penh.

As the senior surviving member of the Khmer Rouge regime, his arrest had been widely expected.

Witnesses say he appeared calm and cooperated fully with the authorities.

"There were many rumors in the media that something was going to happen as soon as Friday, so it's pretty safe to say that he was probably not unprepared for something like this to take place," said Peter Foster, the official spokesman for the U.N. side of the joint Cambodian-U.N. Khmer Rouge Tribunal.

Noun Chea was right-hand man to Khmer Rouge leader Pol Pot and was known as "Brother Number Two" in the regime's all-powerful five-man inner circle.

The ultra-Maoist group forced Cambodians to work in labor camps in their drive to create a utopian, classless society. Almost two million people died from starvation, overwork or murder.

Youk Channg is the director of the Documentation Center of Cambodia, which is compiling evidence on the Khmer Rouge regime ahead of the upcoming tribunal.

He says Noun Chea is likely to blame foreign powers for most of the killing.

"He blames the foreigners for what happened here. He blames the Indochina War, you know, things like that," he said. "But, he denies knowing about the number of people who have been killed or died at that time, for example. He has repeatedly stated that, you know, we only look at one side of the KR, the bad side of it, you know - Khmer Rouge [is] equal to bad forever - that is his defense. That's why we need the tribunal, for him to come and defend and let us understand."

The Tribunal plans to prosecute at least five former Khmer Rouge leaders for crimes against humanity. Foster says the arrest of Noun Chea marks an important milestone in bringing those responsible for Cambodia's genocide to justice.

"Today we brought into the facility the most senior surviving member of the Khmer Rouge regime and I think this will go a long way - I hope this will go a long way - to convince those critics that the ECCC is serious about fulfilling its mandate and bring the senior leaders and those most responsible to justice," he said.

Noun Chea is to be informed of the charges against him and advised of his legal options.

The arrests of the other three former Khmer Rouge leaders are expected soon.