PAILIN, Cambodia – Police arrested the top surviving Khmer Rouge leader today, taking Nuon Chea to appear before a U.N-backed genocide tribunal for his role in the 1970s Cambodian regime blamed for the deaths of 1.7 million people.

Police surrounded his home in Pailin in northwestern Cambodia near the Thai border and served him with an arrest warrant on charges of crimes against humanity, police Captain Sem Sophal said.

Officers later took the 82-year-old Nuon Chea — who denies any wrongdoing — into custody and put him into a car and then a helicopter headed for the capital, Phnom Penh, as his son and dozens of onlookers gathered to watch in silence, witnesses said.

“My father is happy to shed light on the Khmer Rouge regime for the world and people to understand,” Nuon Say said afterward.

In Phnom Penh, a convoy transported Nuon Chea from a military airport in the capital to the tribunal’s offices. Tribunal spokesman Reach Sambath said the co-investigating judges were expected to question Nuon Chea later today.

Nuon Chea helped Khmer Rouge leader Pol Pot seize control of Cambodia’s underground communist movement in the 1950s and ’60s.

He later became the group’s chief political ideologue during its murderous rule in the 1970s, when its radical policies caused the deaths of 1.7 million people through hunger, disease, overwork and execution.

Nuon Chea has consistently denied any responsibility for the mass brutality and told The Associated Press in a July interview that he was ready to be judged by an international tribunal.

“I was president of the National Assembly and had nothing to do with the operation of the government,” he told the AP. “Sometimes I didn’t know what they were doing because I was in the assembly.”

“I will go to the court and don’t care if people believe me or not,” he said.

The U.N.-backed genocide tribunal investigating crimes by the Khmer Rouge was created last year after seven years of contentious negotiations between the United Nations and Cambodia.

Critics have warned that Nuon Chea and the other former Khmer Rouge leaders would die before ever seeing a courtroom.

Prosecutors for the tribunal have said there are five senior Khmer Rouge figures they have recommended for trial. Nuon Chea is the second, and highest-ranking, Khmer Rouge leader detained to appear before the panel.

Kaing Guek Eav — commonly known as Duch, who headed the former Khmer Rouge S-21 prison — was the first suspect detained by the tribunal on charges of crimes against humanity. He was charged last month. The other suspects have not been publicly named.

Theary Seng, a Cambodian-American who lost relatives to the Khmer Rouge atrocities, said she was elated by the news of Nuon Chea’s arrest.

“To have another name soon made public and to know that it is Nuon Chea, who is the Brother No. 2 in the reign of terror, is very encouraging,” said Theary Seng, the director of Center for Social Development, a nonprofit group monitoring development of the Khmer Rouge tribunal.

The late Khmer Rouge leader Pol Pot died in 1998 and his former military chief, Ta Mok, died in 2006 in government custody.

Their senior-level colleagues, Ieng Sary, the former foreign minister; and Khieu Samphan, the former head of state, live freely in Cambodia but are in declining health. They are also widely believed to be on the prosecutors’ list.

With a $56.3 million budget limited to three years, trials had been expected to start this year.

But Cambodian and foreign judges spent much of the year bickering about rules and protocols, including the setting of expensive legal fees for foreign lawyers wanting to take part in the proceedings.

The tribunal is an unprecedented hybrid, with Cambodian judges holding the majority in decision-making matters but needing one supportive vote from a foreign counterpart to reach a super-majority to prevail.

It is operated under the Cambodian judicial system, often described by critics as weak, corrupt and susceptible to political manipulation.