Couillard said he was questioned by UPAC as party leader, but is not personally under investigation.
He said the officers questioned him about party practices and that names of certain individuals came up during the conversation, though he is not authorized to divulge that information.
This week, Couillard confirmed that police had raided his party's offices last July.
- Quebec Liberal headquarters raided by anti-corruption unit
Couillard said he decided to go public about the interview in the spirit of transparency, because he wants to restore the public's faith in politicians.
"Certainly the way we practice politics at the party level has been helped tremendously by the succession of actions that started three or four years ago, with the police units that were created and the Charbonneau Commission," said Couillard.
Couillard said if the police interview anyone in authority at the Quebec Liberal Party, he will make that information public.
Coalition Avenir Québec justice critic, Jacques Duchesneau, said Couillard did the right thing when he disclosed he had been interviewed, but should have been more forthcoming informing the public about the raid.
"Couillard did today what he should have done last July," said Duchesneau.