A technician hired by Hillary Clinton to run the private email system she used while U.S. secretary of state told investigators he tried to pass on colleagues' concerns that the system might not comply with records laws, FBI interview summaries show.

Bryan Pagliano, the technician Clinton hired when she joined the State Department in 2009, told federal investigators he relayed the concerns to Cheryl Mills, then Clinton's chief of staff.

Mills, whose lawyer did not respond to requests for comment, has previously testified under oath she could not recall anyone alerting her to potential problems with Clinton's email arrangement.