Story highlights Bryan Pagliano has come under scrutiny over the past year for his role in setting up Hillary Clinton's private email server

On Monday, a State Department spokeswoman confirmed his emails are still missing

(CNN) The State Department has not been able to locate emails sent and received by IT staffer Bryan Pagliano during Hillary Clinton's tenure as Secretary of State, according to a filing by the Republican National Committee, which is suing the Department for those records.

Pagliano has come under scrutiny over the past year for his role in setting up Clinton's private email server -- the existence of which has outraged Clinton's critics and led to allegations she mishandled government information.

Pagliano refused to answer questions about the server when interviewed by a congressional committee last year, but accepted an immunity offer from the Justice Department in March. Since then, Pagliano has been interviewed by the FBI, which is investigating Clinton's use of the private server.

The State Department first acknowledged the missing emails in December. On Monday, a State Department spokeswoman confirmed the emails are still missing.

"We are continuing to search for Mr. Pagliano's e-mails which the Department may have otherwise retained," said Elizabeth Trudeau, Director of the Office of Press Relations, adding that employees are responsible for archiving their official emails under the Federal Records Act.

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