Former Philippine president Rodrigo Duterte's deadly war on drugs has always faced strong opposition on the home front.

This week, he was arrested and transferred to the International Criminal Court at The Hague to face crimes against humanity charges.

AFP speaks to four key opponents of Duterte's years-long crackdown against drug users and dealers that rights groups say killed tens of thousands of people.

The news of Duterte's arrest on Tuesday took several minutes to sink in for rights advocate Father Flaviano Villanueva. But when it did, the Manila-based priest told AFP that he immediately thought: "God never sleeps."

Villanueva has spent years assisting the families of those killed in the drug crackdown.

He said he told the widows he works with that "justice comes in different shapes".

"Legal justice is an expression of healing, especially in this situation, where Duterte's arrest is a manifestation of him paying for his sins."

But the killings were not solely the former president's........

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