Candidates linked to Philippine ex-leader Rodrigo Duterte appear to have won election victories, including Duterte himself, despite him being detained for alleged crimes against humanity.

Former Philippine President Rodrigo Duterte was almost certain to be elected mayor of his home city by a landslide on Monday, unimpeded by his detention at the International Criminal Court on charges of murder as a crime against humanity.

Nicknamed "the Punisher" and "Dirty Harry", Duterte served as Davao's mayor for two decades before becoming president. Now he has been reelected despite facing charges linked to a brutal war on illegal drugs.