Former Philippines president Rodrigo Duterte has been placed on a plane to the Netherlands following his arrest in Manilla, international news agencies said on Tuesday afternoon.

Duterte, 79, was arrested on behalf of the International Criminal Court in The Hague where he faces charges of involvement in crimes against humanity during his “war on drugs”, according to news agency Reuters. He had just arrived in the capital from Hong Kong.

His youngest daughter Veronica said on Instagram her father had boarded the plane but the family had not been informed of its destination.

The ICC began its investigation into Duterte in 2018 and according to the New York Times, the arrest warrant had been kept secret.

He unilaterally withdrew the Philippines from the court’s founding treaty in 2019.

Duterte came to power on a pledge to kill thousands of drug pushers and user although estimates vary about how many people were actually killed. Based on police data, the death toll was 6,000 but independent monitors believe the number of extrajudicial killings could be much higher.

The ICC declined to comment on the report that the former president had been arrested on its behalf.

The agency’s website states that the investigation into the Philippines covers “any alleged crime within the jurisdiction of the court… committed in the Philippines between 1 November 2011 and 16 March 2019 in the context of the so-called ‘war on drugs’ campaign”.

Duterte is not mentioned by name.