Philippine President Rodrigo Duterte (R) talks to Philippine National Police (PNP) chief Ronald Dela Rosa during the oath-taking of the newly promoted officials of the PNP at the Malacanang presidential palace in metro Manila, Philippines January 19, 2017. REUTERS/Romeo Ranoco

MANILA (Reuters) - Philippine President Rodrigo Duterte has stood by his police chief after calls for him to resign over the alleged killing of a South Korean businessman by police officers at the national police headquarters.

Ronald Dela Rosa, a top figure in Duterte’s deadly war on drugs, has the president’s full support, the president’s top aide, Christopher Go, told Reuters on Sunday.

A number of lawmakers, including Duterte’s ally, House Speaker Pantaleon Alvarez, have called on Dela Rosa to step down after several officers were charged with kidnapping and killing Jee Ick-joo inside the headquarters in October.

Dela Rosa said on Thursday he was “very angry” and “very offended” about the case.

Rights groups say abuses of police power are rampant and accuse police of killing suspected drug dealers as part of Duterte’s narcotics crackdown.

“A genuine recognition of the root of the problem should go beyond blaming Dela Rosa, and instead condemn the drug war policy that has produced human rights violators and criminals out of the men and women of the PNP (Philippine National Police),” Senator Leila De Lima said in statement over the weekend.

Police figures show more than 7,000 people have been killed during Duterte’s campaign.

Police deny deliberately carrying out extrajudicial killings and say deaths caused in the course of the anti-drugs campaign have been in self-defense.