MANILA - Philippine prosecutors on Thursday filed murder charges against leading opposition senator Panfilo Lacson over the murder of two men nine years ago when he was national police chief.

Senior state prosecutor Peter Ong said testimony from witnesses and evidence gathered by justice department agents justified the decision to charge Lacson with the kidnapping and murders.

After the filing of charges in a local court, the court is usually given 10 days to decide whether to issue a warrant of arrest, or to dismiss the case.

Prosecutors previously said Lacson ordered the November 2000 killings of publicist Salvador "Bubby" Dacer and driver Emmanuel Corbito when he was police chief under then-president Joseph Estrada.

Estrada was toppled in 2001 in a military-backed popular uprising spawned by a corruption scandal. He was convicted of massive graft in 2007 but Arroyo pardoned him six weeks later.

Philippine media have suggested Dacer was killed because he knew something about the anomalies of the Estrada administration.

Lacson has previously insisted he was innocent, saying the accusations were a case of political persecution for his role as a critic of President Gloria Arroyo. Estrada has also denied any involvement in the murders.