MANILA (2nd UPDATE) - Magdalo party-mates Rep. Gary Alejano and Sen. Antonio Trillanes IV have filed a supplemental complaint against President Rodrigo Duterte before the International Criminal Court (ICC).

The complaint, filed Tuesday, was in support of the April complaint filed by lawyer Jude Sabio against Duterte and his senior officials before the ICC over allegations of crimes against humanity in relation to his administration's nationwide crackdown on narcotics.

TIGNAN: receiving copy ng supplemental complaint na isinampa nina Sen. Trillanes at Rep. Alejano sa ICC laban kay Pang. Duterte pic.twitter.com/g3PUujzGXh

— Zandro Ochona (@ZandroDZMM) June 6, 2017

Alejano and Trillanes urged the ICC to conduct a preliminary probe into allegations of extra-judicial killings and "provide a glimmer of hope for the thousands of victims that Duterte's impunity would soon end."

"The case of crimes against humanity against Duterte is very solid. He repeatedly, explicitly and clearly pronounced a national policy of killing drug suspects and the PNP executed it. Moreover, the Philippines, being a state party and Duterte being a Filipino, satisfy jurisdictional requirements. Any Filipino lawyer who says otherwise, should read the ICC policy papers first," Trillanes said in a press release Tuesday.

The move came after lawmakers last month thumbed down an impeachment complaint filed by Alejano against the chief executive for lack of sufficiency in substance.

Sabio, who is also the lawyer of confessed hitman Edgar Matobato, said in his 77-page complaint that Duterte "repeatedly, unchangingly and continuously" committed crimes against humanity and that under him, killing drug suspects and other criminals has become "best practice."

Duterte has downplayed the complaint saying "If I go to prison, so be it."

“Let them be. Nobody can stop them from filing,” Duterte previously told reporters on the sidelines of a joint press conference with Sultan Hassanal Bolkiah of Brunei, who was in Manila on a state visit last April.