The Philippines’ firebrand former leader Rodrigo Duterte was arrested on Tuesday at the request of the International Criminal Court, a major step in its investigation into thousands of alleged extrajudicial killings in a bloody “war on drugs” that defined his presidency.

Duterte was served an Interpol arrest warrant on his arrival at Manila’s main airport and was in custody, the office of President Ferdinand Marcos Jr said in a statement.

The “war on drugs” was Duterte’s signature campaign policy that swept the maverick, crime-busting mayor to power in 2016, delivering on promises he made during vitriolic speeches to kill thousands of narcotics dealers.

Duterte, 79, has repeatedly defended the crackdown. He denies ordering the murders of drug suspects and said he instructed police to kill only in self-defence.

The arrest follows years of Duterte taunting the ICC since he unilaterally withdrew the Philippines from the court’s founding treaty in 2019 as it started looking into allegations of systematic extrajudicial killings on his watch.

The Philippines had until last year refused to cooperate with an investigation into alleged crimes against humanity by the ICC, which says it has jurisdiction to probe incidents while a country is a member.

In a video posted on Instagram by daughter Veronica Duterte from his custody at Manila’s Villamor Air Base, Duterte questioned the reason for his arrest.

“What is the law and what is the crime that I committed?” he said in the video. It was unclear who he was speaking to.

“I was brought here not of my own volition, it is somebody else’s. You have to answer now for the deprivation of liberty.”

SLUMLAND KILLINGS

According to police, 6,200 suspects were killed during anti-drug operations that they say ended in shootouts. But activists say the real toll of the crackdown was far greater, with thousands of slumland drug users, many of whom were included on official “watch lists”, killed in mysterious circumstances.

Police deny involvement in those killings and reject allegations from rights groups of systematic executions and cover-ups.

News outlets earlier on Tuesday showed video footage of Duterte dressed in a jacket and striped polo shirt and walking casually through a corridor at the airport upon his return from Hong Kong, accompanied by members of the police Criminal Investigation and Detection Group and uniformed officers close by.

Duterte’s ally and former legal counsel Salvador Panelo said the arrest was unlawful and police had denied the former president legal representation.

“The ICC arrest warrant comes from a spurious source, the ICC, which has no jurisdiction over the Philippines,” Panelo said in a statement.

Human Rights Watch called the arrest “a critical step for accountability in the Philippines” and said authorities should swiftly hand Duterte over to the ICC.

“His arrest could bring victims and their families closer to justice and sends the clear message that no one is above the law,” it said in a statement.