"We can confirm a D&O probe into First Republic is taking place," a spokesperson told Reuters, referring to the bank's directors and officers. The regulator did not provide further details.

The investigation, which has not previously been reported, is the third the FDIC has opened into bank failures earlier this year which cost the federal government's deposit insurance fund about $32 billion.

(Reporting by Douglas Gillison and Christine Prentice; editing by Michelle Price)

By Douglas Gillison and Chris Prentice