WASHINGTON - Republican lawmakers are expressing frustration about what they say is a lack of information from the Justice Department about Hillary Rodham Clinton's use of a private email account while serving as secretary of state.

Published reports this week cited anonymous government officials as saying the FBI has succeeded in recovering deleted emails from Clinton's server.

The Democratic presidential candidate provided the device to the FBI last month and has said emails had been removed. Federal investigators are looking into Clinton's home-based server amid concerns that classified information may have passed through the system.

The chairman of the Senate Judiciary Committee, Republican Chuck Grassley of Iowa, says the Justice Department is keeping him in the dark about whether a criminal investigation is underway into Clinton's use of private email.