Justice Secretary Fredderick Vida on Tuesday declined to say whether former Department of Public Works and Highways Secretary Manuel Bonoan would be required to return alleged proceeds from the flood control scam in exchange for becoming a state witness.

Vida refused to comment when asked if Bonoan, like four other witnesses in the flood control investigation, would be required to make restitution to the government.

"I have no idea on that. I cannot comment," Vida said when asked whether Bonoan had agreed to return any funds.

Pressed further on whether Bonoan should also make restitution, Vida replied: "I have no comment on that."

The issue surfaced a day after Ombudsman Jesus Crispin "Boying" Remulla announced that Bonoan would be turned into a state witness despite being a respondent in a plunder case pending before the Sandiganbayan.

Remulla said prosecutors had already filed a motion before the anti-graft court's Fifth Division seeking Bonoan's discharge from the case, in which Sen. Jinggoy Estrada is among the accused.

The question of restitution arose because at least four individuals admitted into the Witness Protection Program in connection with the alleged flood control anomalies had returned millions of pesos to the government.

Those who made restitution were former DPWH district engineer Henry Alcantara, former DPWH undersecretary Roberto Bernardo, former DPWH engineer Gerard Opulencia, and private contractor Sally Santos.

Combined, the four returned at least P316.351 million in alleged ill-gotten funds.

Government officials have yet to say whether Bonoan will likewise be required to return funds as part of any agreement to testify for the prosecution.