The planned parallel probe of the Senate into the bloody drug war of the administration of former president Rodrigo Duterte may be "biased" given that it would be no less than Senator Ronald "Bato" de la Rosa, the chief enforcer of the anti-narcotics campaign, who will spearhead the hearing. 

Manila Rep. Bienvenido Abante Jr., co-chair of the House quad committee, said this in a briefing on Wednesday, just hours after De la Rosa announced that they will launch a motu proprio into the war on drugs.

Abante questioned De la Rosa's ability to remain impartial given his deep involvement in the controversial war on drugs and close ties with Duterte.

"He will not be fair. He became the [chief] of the Philippine National Police (PNP) during the time of the former president. So, I would think that he would be more biased than actually balanced in that hearing," Abante told reporters. 

De la Rosa announced they will start the investigation even if Congress is currently on a break and is cocksure that his former boss Duterte will face the Senate hearing. 

De la Rosa had been repeatedly invited to the House inquiry to shed light on the allegations that the police committed extrajudicial killings (EJK) but asserted he would not grant such, citing parliamentary courtesy between members of Congress. 

The former president, who also thumbed down previous summons, recently implied that he would face the quad comm probe on a condition that only "educated questions" would be raised.

Abante confirmed that the quad comm will definitely invite Duterte to the subsequent hearings and will be given top priority. 

"If we're going to invite the former president, we won't invite too many resource persons so he could be able to freely say his piece," he stated.

Duterte's alleged trusted aide, retired police colonel Royina Garma, confirmed to the quad comm last week that the Duterte administration mimicked the so-called "Davao model," a system rewarding police for killing drug suspects as high as P1 million on a national scale. 

According to Garma, 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.

She claimed that the monetary rewards for drug-related killings ranged from P20,000 to P1 million, depending on the prominence of the target.

De la Rosa and another Duterte long-time ally, Senator Christopher "Bong" Go, denied Garma's allegations.

Go, whom Garma said oversaw the brutal drug war by weekly reporting to Duterte the number to request refunds for operational expenses, labelled Garma's accusation as "malicious" and "unsubstantiated."

In 2016, Duterte admitted the existence of EJK but contended that it was not state-sponsored. 

The quad comm suspects that the Duterte administration sourced the funding for the supposed cash rewards to the police in its intel funds, citing fluctuations in its use within certain months.

Abante and co-chair, Santa Rosa Rep. Dan Fernandez, said that the mega-panel would formally seek the assistance of the Anti-Money Laundering Council this week to track the full extent of cash flow tied to drug war operations since the funds were funnelled through the banking system. 

The financial probe is being viewed as a critical step in the panel's investigation into Duterte's drug war. By determining the source of the funds and identifying the recipients, the quad comm seeks to reveal the financial networks behind the extrajudicial killings, potentially exposing key figures who profited from the violence.

This deeper look at financial flows could link high-ranking officials to the operations, uncovering the full extent of accountability in the war on drugs.

The government lodged more than 7,000 deaths under Duterte's notorious drug war.

Local and international human rights organizations, however, estimated that the death toll exceeded 30,000, affecting predominantly low-income families and communities.