The Office of the Ombudsman said it will challenge the Sandiganbayan's decision granting bail to former Sen. Ramon "Bong" Revilla Jr. and vowed to exhaust all available legal remedies, maintaining that it has strong evidence against the former lawmaker.

While respecting the anti-graft court's ruling, the Ombudsman said it remains firm in its investigation into Revilla's alleged involvement in a ghost flood control project in Bulacan.

"We will exhaust all legal remedies to highlight the basis for which we can say that evidence of guilt is indeed strong against former Senator Ramon 'Bong' Revilla Jr.," the Ombudsman said in a statement.

The Sandiganbayan Third Division granted Revilla's petition for bail after finding that the prosecution failed to establish strong evidence of guilt during the bail proceedings. However, it denied the bail petitions of his co-accused from the Department of Public Works and Highways (DPWH).

In its 2-1 ruling, the anti-graft court said the prosecution failed to show how Revilla facilitated the inclusion of the projects in the national budget or that he knew the alleged advance kickbacks he received would come from the commission of malversation once the projects were implemented.

The court also ruled that the money allegedly received by Revilla came from contractors and did not constitute public funds.

The Sandiganbayan stressed that its finding that the evidence of guilt was not strong for purposes of bail does not amount to a finding of reasonable doubt, noting that the prosecution has yet to present its evidence-in-chief during trial.

Revilla posted a P1-million bail on Friday evening and was subsequently released from the Quezon City Jail.