MANILA - An international rights group on Tuesday renewed calls for the United Nations to probe drug-related killings in the Philippines after a retired policeman bolstered allegations that President Duterte ordered assassinations by an alleged death squad.

"The allegations by former police officer Arturo Lascañas -- that President Rodrigo Duterte, when mayor of Davao City, ordered the killing of several people -- heighten the urgent need for an independent United Nations investigation into more than 7,000 people in Duterte's 'war on drugs' to uncover ultimate responsibility for those crimes," said Phelim Kine, deputy Asia director at Human Rights Watch.

Lascañas alleged Monday that Duterte paid millions of pesos for the alleged Davao Death Squad to carry out hits.

• Lascañas list: Alleged sins of the Davao Death Squad

His account corroborated that of confessed hit man Edgar Matobato, who testified at a Senate inquiry to personally watching Duterte give orders for police to kill suspected criminals.

Kline said the disclosures strengthen allegations that the Duterte administration was politically-motivated in pursuing cases against Senator Leila de Lima, who as investigated alleged DDS crimes as former chair of the Commission on Human Rights.

"The authorities should immediately drop all charges against Senator de Lima, cease their harassment of her and cooperate fully with a UN probe," Kine added.

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