The Philippines’ Office of the Ombudsman on Monday filed a plunder case against former House Speaker Martin Romualdez, a cousin of President Ferdinand Marcos Jr, according to a court filing.

The case stems from Romualdez’s alleged role in the multi-billion-peso graft scheme involving funds for flood infrastructure projects. Romualdez has repeatedly denied wrongdoing.

Investigators earlier alleged that Romualdez, ex-lawmaker Zaldy Co and other personalities conspired to unlawfully accumulate ill-gotten wealth from infrastructure funds.