Former Philippine president Rodrigo Duterte has been charged with crimes against humanity by the International Criminal Court (ICC).

The 80-year-old is accused of being criminally responsible for dozens of murders that allegedly took place as part of his so-called war on drugs, during which thousands of small-time drug dealers, users and others were killed without trial.

Duterte is the first Asian former head of state to be indicted by the ICC.

ICC deputy prosecutor Mame Mandiaye Niang said Duterte was an "indirect co-perpetrator" in the killings, which the court alleges were carried out by others, including police.

A redacted version of the ICC's charge sheet was only made public on Tuesday AEST.

The first count against Duterte relates to his alleged indirect co-perpetration in the m

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