Judges at the International Criminal Court have approved a formal investigation into possible crimes against humanity allegedly committed under the leadership of Philippine President Rodrigo Duterte in the context of his "war on drugs".
The judges approved a request by the court's prosecutor to begin the investigation into potential murder as a crime against humanity.
Their assessment of material presented by prosecutors, who had asked for permission to investigate, was that "the so-called 'war on drugs' campaign cannot be seen as a legitimate law enforcement operation," but rather amounted to a systematic attack on civilians.
The war on drugs was launched by Duterte after he was elected president in 2016 on an anti-crime platform.
The 76-year-old leader, whose term ends next year, has vowed not to cooperate with the ICC if an investigation were to be launched.
Human rights groups accuse Duterte of inciting deadly violence and say police have murdered unarmed drug suspects on a massive scale as part of the campaign.
Police deny this and Duterte says the police are under orders to kill only in self-defence.
In July, Duterte attacked the court, saying he would continue his fight against drugs.
"I have never denied (it), and the ICC can record it: those who destroy my country - I will kill you," he said.
Although the Philippines has withdrawn from membership of the ICC, it was a member between July 2016 and March 2019, the period covered by the prospective investigation.
The judges said that relevant crimes appeared to have continued after that date but that the court was limited to investigating those suspected to have occurred while the Philippines was a member.
Australian Associated Press