Senator Antonio Trillanes has filed administrative and criminal charges against Presidential Communications Assistant Secretary Mocha Uson.
The cases include libel.
Trillanes went to the Ombudsman on Friday to submit the complaints.
The charges come after Uson accused the senator of allegedly maintaining bank accounts in Singapore.
She posted this allegation on her social media account.
Trillanes labelled Uson's claim as fake news.
He flew to Sinapore to prove he has no offshore bank accounts.
Magdalo Representative Gary Alejano accompanied Trillanes in filing the cases at the Ombudsman.