THE Davao Death Squad (DDS), a vigilante group allegedly behind the execution of suspected criminals in southern city, was allegedly getting orders from Davao City Mayor Rodrigo Duterte, Justice Secretary Leila de Lima said Tuesday.

De Lima told reporters that this was the claim of a witness, a former member of the DDS and who is now under the custody of the National Bureau of Investigation (NBI) under the Department of Justice's (DOJ) Witness Protection Program.

Asked if the witness has personal knowledge on Duterte's alleged involvement with DDS, she said, "yes."

"Iyong witness namin pinangalanan niya kung sino 'yung mga gumagawa niyan allegedly on orders of Mayor Duterte," she said.

She said the NBI is now in the process of case build-up against Duterte and other alleged members of DDS.

"Pinapa-validate ko 'yung mga storya niya if we can have corroborative evidence on each and every incident na isinalaysay niya diyan sa kanyang sinumpaang salaysay para sigurado na malakas ang kaso kapag na-file na namin," de Lima said.

She said that the NBI is not mandated or obliged to summon Duterte on its probe.

"Ang importante ay makahanap ng sapat na ebidensya," the DOJ chief added.

The New York-based international Human Rights Watch (HRW) has urged the Philippine government to probe Duterte for his alleged link to death squad.

It said that the Philippines should not tolerate any government official who openly endorses extrajudicial killings to prevent crimes from happening.

Duterte allegedly publicly acknowledged that Davao City was among the safest cities in the world because they killed criminals in their area.

The mayor has since denied involvement with the DDS and ordering the police to kill criminals.

He also challenged de Lima and the HRW to file a case against him in court. (SDR/Sunnex)