The revelation of retired police colonel Royina Garma about the highly controversial war on drugs of the Duterte administration involving an alleged cash reward system could just be the "tip of an iceberg" that requires attention and a rigorous probe, House leaders said Sunday.

Assistant Majority Leaders Jefferson Khonghun and Paolo Ortega said the gravity of Garma's allegations cannot be merely discounted considering how she had been closely associated with Duterte, who appointed her as Philippine Charity Sweepstakes Office general manager in June 2019, barely two weeks after availing early retirement.

“Mind you, it’s just the tip of the iceberg – so to speak. It comes from the perspective of an insider who has not just the trust and confidence, or the eyes and ears of the former president, but even beyond that,” said Khonghun.

He also did not dismiss the possibility that the retired police, who has been identified as Duterte’s trusted aide, may stand as a “credible” source to the ongoing investigation of the House quad comm into the previous administration’s notorious bloody anti-drug campaign.

Ortega, in the same vein, said the government should “take note of Garma’s explosive testimony” as he suspects that it was only a peek into the deeper and alarming inner workings of the Duterte administration on the alleged extrajudicial killings (EJK).

“There is much more to uncover, and we are committed to getting to the bottom of these serious allegations. The quad comm will not stop until all the facts are laid bare because this is about accountability,” Ortega said.

To recall, Garma left lawmakers surprised on Friday by changing her tune and implicated former boss Duterte in ordering police to mimic the so-called “Davao model," a system rewarding police for killing drug suspects as high as P1 million, on a national scale.

She disclosed that an assembly was held in May 2016, a month before Duterte took office, to discuss the creation of a task force that would implement the nationwide killing.

Garma claimed Duterte wanted a police officer who is a member of Iglesia Ni Cristo to spearhead the special task force. As a result, she recommended Police Lt. Col. Edilberto Leonardo, who was then assigned to the PNP Criminal Investigation and Detection Group.

Leonardo, who is being linked as the brain behind the ambush plot of PCSO board secretary Wesley Barayuga in July 2020 allegedly in cahoots with Garma, resigned from his post as chief of the National Police Commission last week.

Duterte, who had openly declared a shoot-to-kill order to the police, is now the subject of a looming probe by the International Criminal Court (ICC).

Former senator Leila de Lima, who was then put behind bars for allegedly criticizing Duterte’s drug war since he was still a Davao City mayor, deemed as “perfect” Garma’s testimony, which she implied should be submitted to the ICC.

“The events of the quad committee must be conveyed to The Hague, especially now that those involved in the killing of thousands of Filipinos started to point fingers. Justice should be pursued relentlessly both here and at the ICC so as not to give the guilty any chance of escaping judgment and punishment,” she wrote in Filipino in a post on X formerly Twitter.