House leaders didn't mince words on Thursday in blasting the relentless efforts of Senator Ronald "Bato" de la Rosa's panel in investigating the "baseless" allegations linking President Ferdinand Marcos Jr. to illegal drug use, deeming it a "clear waste of time."

Deputy Majority Leader Jude Acidre was puzzled over the Senate's aggressiveness in probing the so-called Philippine Drug Enforcement Agency's (PDEA) leak documents showing Marcos' involvement in narcotics drugs when it could have invested its efforts in passing Marcos administration's priority legislation, including the proposed New Government Procurement Act, which already passed by the House as early as December last year.

"There are plenty of laws that the larger chamber had passed that are still [pending] in the Senate that I think warrants more of their time and attention," Acidre said in a press briefing.

"I hope Senator Bato will realize that it will not help the Senate as an institution that issues like this that have no basis are given air time."

The Senate Committee on Public Order and Dangerous Drugs, chaired by De la Rosa, will carry on with its third motu proprio hearing next week to scrutinize further the veracity of the allegations leveled by former PDEA intelligence officer Jonathan Morales against Marcos.

Morales claimed that he has a list of supposed big-time personalities engaged in illegal substance use, including the President and actress Maricel Soriano in 2012.

Deputy Majority Leader Faustino "Inno" Dy, meanwhile, posits that the insistent probing of De la Rosa's committee into the allegations, notwithstanding the document's lack of authenticity, only indicates that the senator has an ulterior motive.

"For me this is a dead end. This is not going anywhere. But if we insist on this matter, there is a motive, there is clearly a motivation why someone would keep pushing, will keep pushing for this to really malign someone, malign our president, malign the actress that was also involved, Maricel Soriano," Dy said.

Both Acidre and Dy have speculated that the timing of the probe may have been intentional to revert the public's attention to the current admin's issues while isolating the Philippines' reentry into the International Criminal Court (ICC).

De la Rosa, the Philippine National Police's (PNP) erstwhile chief during Duterte's administration and who served as the architect of the deadly drug war, was among Philippine officials who wanted to be probed by investigators of the ICC on the massive killings.

"[The PDEA issue was] 12 years ago. So why is it coming out now? What is the reason? Who makes it as a big deal? f this is not part of a destabilization plot, I really don't know what to call it," Acidre said.

"It's surprising that it will reach third hearing. This is a clear waste of time, waste of taxpayers' money," Dy chimed in.

No less than Senate President Juan Miguel "Migz" Zubiri flagged the continuing probe of De la Rosa's panel, notwithstanding the lack of documentary evidence to support Morales' claim.

"In other words, this was solely based on the testimony of one person based on what appears to be hearsay evidence," Zubiri said.

Duterte earlier accused his successor Marcos of being "stoned" and a "drug addict", whose name, he alleged, was on PDEA's drug watch list.

The PDEA has denied the allegations, saying Marcos was never listed for illegal drug use.