WASHINGTON—Former Secretary of State Hillary Clinton’s emails from her time in government were deleted off her server late last year, her attorney said on Friday.

Responding to a subpoena from a congressional committee investigating the Benghazi attacks, attorney David Kendall said Mrs. Clinton’s email server no longer contained any records from her time in office and declined to submit it to a third-party for review and analysis.

“There are no hdr22@clintonemail.com emails from Secretary Clinton’s tenure as Secretary of State on the server for any review, even if such review were appropriate or legally authorized,” Mr. Kendall said, referring to the email address Mrs. Clinton used.

Republicans in Congress are probing Mrs. Clinton’s exclusive use of a personal email account for government business run off her own personal server. The Benghazi committee subpoenaed Mrs. Clinton’s email records earlier this month and requested that she turn over her email server to a neutral, third-party arbiter for examination and review.

The widening congressional probe has threatened to overshadow the launch of Mrs. Clinton’s 2016 presidential campaign, which is expected to happen in the coming weeks.