The International Criminal Court's pre-trial chamber looking into the case of former President Rodrigo Duterte found him "individually responsible for the crimes against humanity of murder" in connection with the killings blamed on his war on drugs.

According to the warrant of arrest on Duterte, the pre-trial also said there was "no reasonable expectation" that he would cooperate with the tribunal.

"Taking into account the totality of the information before it, the Chamber finds reasonable grounds to believe that Mr. Duterte is individually responsible for the crime against humanity of murder as an indirect co-perpetrator within the meaning of Article 25 (3)(a) of the Statute, committed during the relevant period," read the document tagged "secret."

"After evaluating the information submitted by the prosecution, the Chamber accepts that there is no reasonable expectation that he would cooperate with a summons to appear issued by the Court. The chamber observes that Mr. Duterte, even though no longer the President of the Philippines appears to continue to wield considerable power," it added.

Duterte in a speech in Hong Kong on Sunday said his actions when he was president were meant to ensure peace and order in the country.

"Ano man ang kasalanan ko, ginawa ko ‘yun para magkaroon ng konting katahimikan at mapayapa ang buhay ng Pilipino," he added.

(Whatever my sins may be, I did them to bring some peace and security to the Filipino people.)

Former chief presidential legal counsel Atty. Salvador Panelo said Tuesday the arrest of former President Rodrigo Duterte was unlawful.

In a statement, Panelo said the Philippine National Police did not allow one of Duterte’s lawyers to meet him at the airport and to question the legal basis for Duterte’s arrest.

“He was deprived of legal representation at the time of his arrest. The PNP could not have a hard copy [of] the warrant arrest. By not allowing one of his lawyers to meet him, the arresting [officer] could avoid being asked if they have the hard copy of the arrest warrant,” Panelo said.

“It is an illegal arrest because the ICC arrest warrant comes from a spurious source, the ICC, which has no jurisdiction over the Philippines,” he added.

(Reports from GMA Integrated News)