WASHINGTON — The Republican chairman of the House committee investigating Hillary Clinton’s email practices asked a federal prosecutor Tuesday to determine whether she and others working with her played a role in the deletion of thousands of her emails by a Colorado technology firm overseeing her private computer server in 2015.

The written request by Rep. Jason Chaffetz, R-Utah, and obtained by The Associated Press, is based on recent revelations from the FBI, which decided not to press for criminal charges after its own yearlong investigation.

Clinton and her longtime aide and lawyer, Cheryl Mills, told FBI investigators during questioning that they had no knowledge of the technology company’s deletions. Those occurred separately from the email deletions overseen by the former secretary of state’s legal team last year before she turned over 33,000 work-related messages to the State Department. The FBI’s recently released summaries of its investigation did not offer any evidence contradicting their statements.

In a separate letter also obtained by the AP, Chaffetz — the House Oversight and Government Reform Committee chairman — warned the Denver-based tech firm, Platte River Networks, that one of its engineers who deleted Clinton’s electronic files last year could face federal charges of obstructing evidence for erasing the material. That’s because the congressional inquiry into the 2012 attacks in Benghazi, Libya, in which four Americans were killed, had issued a formal order to preserve such records.