MANILA • A retired policeman has tagged Philippine President Rodrigo Duterte in at least three cases of murder, including one involving the summary execution of the entire household of a suspected kidnapping gang financier.

Mr Arthur Lascanas said at a Senate hearing that the killings during Mr Duterte's tenure as Davao mayor were part of a terror campaign waged by "death squads" purportedly on Mr Duterte's payroll, as part of his anti-crime drive in Davao.

He said that "Superman" - supposedly Mr Duterte's code name - had knowledge of, directly ordered, consented to, tolerated and acquiesced to the killings.

In a statement at the start of the hearing, Mr Lascanas said the death squads initially targeted drug pushers and addicts and petty crooks.

"Later on, however, we were ordered by Mayor Duterte to go after and kill his personal and political enemies. We became like hired killers who killed not only criminals but (also) innocent people," he said.

He said that Mr Duterte ordered the killing of a political rival in 2003 and he personally received from Mr Duterte one million pesos (S$28,000) as a "bonus" for the hit.

Mr Duterte's legal counsel, Mr Salvador Panelo, dismissed Mr Lascanas' claims as "fabrications".

"It is out of character for the President to order the killing of a woman, pregnant or not, and for that matter any person. He is outraged by any extrajudicial killing. Neither will he tolerate it," said Mr Panelo in a statement.

Mr Lascanas had also claimed that Mr Duterte's son, Paolo, who is now Davao's vice-mayor, intervened to spare an illegal drug shipment in 2014.

It was at this time that he began doubting Mr Duterte's sincerity in going after drug gangs, Mr Lascanas said, having realised that he and his men were being used as "foot soldiers of drug lords".

"They spared some targets. But for me, I already had both feet in hell because I blindly carried out Mayor Rody's campaign against illegal drugs," he said.

He said he was indirectly involved in the deaths of his two brothers, Cecilio and Fernando, who were involved in drugs. Cecilio was killed in 2011 and Fernando, in 2013.

In all, Mr Lascanas claimed that he killed "almost 200" people as part of the death squads.

He recalled being told by a superior, whom he was ordered to kill for siding with a political rival of Mr Duterte's: "In the business of killings, trust no one." The superior died of a heart attack months later.

Raul Dancel