The State Department cannot find emails sent by former Secretary of State Hillary Clinton’s IT staffer Bryan Pagliano who helped setup Clinton’s private email server, a State Department official told Fox News on Friday.

Alec Gerlach, a State Department spokesman, told Fox News investigators working on recovering Pagliano's emails from the server “have not yet located a .pst that covers the time period of Secretary’s Clinton tenure.”

Politico first reported that state officials told the Senate Judiciary Committee in a closed-door meeting they couldn’t find backup copies of Pagliano’s emails during his work under Clinton when she served as Secretary of State, according to a letter reportedly sent from committee Chairman Chuck Grassley to Secretary of State John Kerry.

The letter, according to Politico, also said the department told the committee the FBI had taken Pagliano’s government computer system, where traces of the messages may be located.

Pagliano plans to invoke the Fifth Amendment to avoid testifying against Clinton, Fox News confirmed in September. Pagliano was asked to testify about the serve by the House Select Committee on Benghazi, the Senate Judiciary Committee and the Senate Homeland Security Committee.

The Washington Post reported in September that Pagliano had been subpoenaed by the Benghazi committee Aug. 11 and committee chairman Rep. Trey Gowdy, R-S.C., had ordered that he appear for questioning on Sept. 10 had also demanded that Pagliano provide documents related to all servers or computer systems controlled or owned by Clinton between 2009 and 2013.

The Post reported in August that Pagliano had worked as an IT director on Clinton's ill-fated 2008 campaign, and was asked to oversee the installation of Clinton's server to handle her correspondence while secretary of state. He was paid by a political action committee tied to Clinton until April 2009, when he was hired by the State Department as an IT specialist. The Post reported that Pagliano left government service in February 2013 and now works for a technology contractor that provides some services to the State Department.

The State Department said it has located a backup for emails Pagliano sent after Clinton left the department, officials cannot find the file for the backup which covers the work he did there, according to Politico.

Grassley has encouraged the State Department to continue searching for Pagliano’s emails by looking at backup files of other workers he could’ve emailed about Clinton’s private server.

Fox News’ Lucas Tomlinson contributed to this report.

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