The FBI is firing staff for political reasons, Democrat senator allegespublished at 16:12 BST 16 September
As the hearing continues, Senator Chris Coons, a Democrat, tells Patel he is concerned the FBI has become political.
Coons mentions Patel has "cleaned house", driving out staff who worked on investigations into President Trump.
Three senior officials who were fired last month sued Patel, claiming they were terminated illegally for political reasons, and at the direction of the White House.
Patel says he disagrees with a lot of Coons' statement - but cites ongoing litigation as a reason he can't respond directly to some claims.