The House Judiciary Committee is seeking to determine whether Attorney General Eric H. Holder Jr. lied under oath during recent testimony before the panel when he discussed a Justice Department investigation into the newsgathering efforts of a Fox News reporter.

The committee sent a letter to Holder on Wednesday asking that he clarify the department's policy on obtaining search warrants for the e-mails of journalists and to explain what he knew about the investigation into Fox News Chief Washington Correspondent James Rosen at the time that he testified before the committee May 15.