The House quad committee wants authorities to initiate a deeper investigation into the supposed link between Davao Rep. Paolo Duterte and alleged cohorts in illegal drug smuggling.

Panel chairperson Ace Barbers made the call late Wednesday as he delivered the committee's progress report, a product of 13 exhaustive hearings into the proliferation of illegal drugs, extrajudicial killings, and the rise of Chinese syndicates linked to Philippine Offshore Gaming Operators.

“Moreover, further investigation should be conducted against, but not limited to, the following individuals: personalities implicated in the illegal drug trade in relation to the revelations provided by resource persons Jimmy Guban and Mark Taguba – Representative Paolo Duterte, Nilo Abellera Jr., Paul Gutierrez, Benny Antiporda, Jojo Bacud, Tita Nanie, and Allen Capuyan,” Barbers said during the last day of session before Congress goes on a month-long holiday break.

In response, Duterte stressed that while he is open to any investigation as he has "nothing to hide," the call for such an investigation should be based on "credible evidence, not on pure hearsay testimony from convicted felons like Jimmy Guban."

"These testimonies, obtained under the guise of a witness protection program in exchange for furloughs, lack credibility and only undermine the integrity of any legitimate inquiry," he retorted late Wednesday.

During the first hearing of the quad committee in August, Guban, a former Bureau of Customs intelligence officer, implicated Duterte, his brother-in-law, lawyer Mans Carpio—the husband of Vice President Duterte—and Michael Yang, former President Rodrigo Duterte's ex-economic adviser, in the smuggling of P11 billion worth of shabu hidden in magnetic lifters at the Manila International Port in 2018.

In November, Mark Taguba, erstwhile BoC "fixer," also faced the quad committee and stood by his testimony before the Senate in 2017 that Rep. Duterte, Carpio, and other members of the so-called "Davao Group" were the perpetrators of the smuggled P6.4 billion shabu seized in Valenzuela in 2017.

Guban and Taguba are currently serving jail time for their alleged involvement in the narcotics trade.

The two had narrated to lawmakers how shipments bypassed inspections through the "Tara system," a renowned scheme in the BoC where drug shipments can successfully pass through screening in exchange for grease money or bribes.

Rep. Duterte had categorically denied knowing Guban, stating they never had any transactions.

He also disclosed on Wednesday that perjury charges—legal consequences a person could face for making false statements under oath—have already been filed against Guban.

"I remain committed to clearing our name and confident that the truth will expose the baseless nature of these accusations," the lawmaker averred.

"This is just the first step in ensuring accountability for those who spread falsehoods and attempt to tarnish reputations with fabricated stories," he added.

Nevertheless, he challenged the entire leadership of Congress to purge the drug menace by beginning to investigate those listed in the Philippine Drug Enforcement Agency watchlist when his father was still president.

"This includes scrutinizing their own members, especially those whose family members have been implicated in drug activities," Rep. Duterte asserted.

Rep. Duterte and Carpio are facing criminal complaints before the Department of Justice over the smuggled shabu in Valenzuela. The complaint was lodged by former Senator Antonio Trillanes IV, a staunch critic of the family.