Did he really kill criminals?
Duterte said that when he was mayor of the southern city of Davao in the Philippines for the ten years from 1988, he used to prowl the streets on a motorcycle "looking for trouble."
"In Davao I used to do it personally. Just to show to the guys [police] that if I can do it, why can't you," he said speaking at a business forum.
"And I'd go around in Davao with a motorcycle, with a big bike around, and I would just patrol the streets, looking for trouble also. I was really looking for a confrontation so I could kill."
Do his comments hold weight?
Justice Minister Vitaliano Aguirre ll dismissed Duterte's claims saying that he is exaggerating to get a message across to the criminals.
"It's like a hyperbole, that's the president, he is used to exaggerate just to put his message across," Aguirre said.
What has he done to fight drug dealers?
Since taking office in June, about 2,000 people have been killed in official anti-drug operations. More than 3,000 other deaths have been perpetrated by unidentified vigilantes.
Duterte has insisted that police only killed in cases of self-defence and said the rest of the killings were committed by gangsters.
The president said he would not prosecute police officers over the extrajudicial killings even if they are found guilty.
How has Duterte reacted to international criticism?
The United Nations and the United States have voiced their concerns. They feel Duterte's statements are a violation of human rights.
But the Philippines leader said US President Barack Obama "should go to hell" and that he was a "son of a whore." Duterte later apologised for the comments.
He has also threatened to pull out of the United Nations.
Rights groups have warned of a breakdown in the rule of law with police and hired assassins operating with complete impunity.