MANILA, Philippines—Lawmakers on Monday said they would audit big drug cases filed in the past and determine whether the alleged bribery that tainted the dismissal of a complaint against the so-called “Alabang Boys” was an isolated incident.

Officers of the Philippine Drug Enforcement Agency (PDEA) who alleged that P50 million was given to state prosecutors and Department of Justice officials dragged into the controversy are scheduled to face off Tuesday in the House of Representatives’ probe of the bribery claims.

Ilocos Norte Rep. Roque Ablan, chair of the House committee on dangerous drugs, said he would ask PDEA officers to present all the evidence to back up their allegation that they were offered bribes in exchange for the release of three rich young men caught peddling drugs.

After the PDEA officers stated their case, the justice officials would present their story, Ablan said. The families of suspects Richard Brodett, Joseph Tecson and Jorge Joseph are expected to be invited to subsequent hearings.

Ablan and the vice chair of his committee met at a Quezon City restaurant on Monday with PDEA Director General Dionisio Santiago, National Bureau of Investigation intelligence chief Ruel Lasala and Dangerous Drugs Board Vice Chair Clarence Oaminal, among others, to discuss their concerns.

Cebu Rep. Antonio Cuenco said lawmakers would also look into the decisions of prosecutors and judges to dismiss drug cases. The committee’s probe would look into drug cases in the past five years.

“We are going to ask the prosecution and the courts as well what happened to these cases. They have been dismissing a lot of strong drug cases indiscriminately. The data that we gather are that in the Philippines, the rate of conviction in drug cases is only 10 percent. In Australia, it’s 80 percent,” Cuenco told reporters.

There have also been instances where drug cases ended up with a certain judge several times and are dismissed, thus earning the magistrates the moniker “dismissing judges,” Parañaque Rep. Roilo Golez said.

Parañaque Rep. Eduardo Zialcita said it was important to find out how many other drug complaints have been tainted with bribery attempts.

“We also want to find out if this is an isolated case or if this is happening all over the Philippines. Because the impression we’re getting is it’s happening regularly,” Zialcita said.

He said he was curious about the fate of six big drug raids conducted in his district.

The committee also approved the suggestion of Tarlac Rep. Jose Yap to hire three lawyers who would follow up on the drug cases and identify the prosecutors and judges who dismissed strong drug cases.

“We have to strengthen the police agencies in this drive against drugs. It’s very important that we know the reason why there is a failure or outright dismissal of cases,” Yap said.

The hearing also intends to come out with new legislation to increase the penalty for bribery—both for the bribe-giver and the bribe-taker, according to Cuenco.