CNN anchor Jake Tapper asked Clinton campaign manager Robby Mook on Sunday to answer why an IT worker who maintained Clinton's private email server referred to a 60-day email-retention policy as a "Clinton cover-up operation."

In an interview on "State of the Union," Tapper asked why an employee of Platte River, which hosted Clinton's private email server, referred to the policy of deleting emails during the time after Clinton was out of office as a "cover-up operation," a comment the IT worker told the FBI was a joke.

"This IT director thought he was covering something up, no?" Tapper asked.

Mook did not address the question specifically, though he did note that the FBI and the Department of Justice chose not to prosecute Clinton over her use of a private email server while serving as secretary of state.

"The FBI did a comprehensive and deep investigation into this, and at the conclusion of that, FBI Director Comey came out and said to the world that there was no case here," Mook said.

Tapper then interjected, pressing more directly.

"What's the Hillary cover-up operation that the IT director is referring too?" Tapper said.

Mook did not address the question again, instead saying the FBI released the information about the IT worker only after House Republicans disclosed information about a deal struck between the FBI and one of Clinton's aides.

"The Republicans on the House side are selectively leaking documents for the purpose of making Hillary look bad," Mook said.

"We've asked the FBI to release all information that they've shared with the Republicans so we can get the full picture. But I would trust the career professionals at the FBI and the Justice Department who looked into this matter, concluded there was no case than I would Republicans who are selectively leaking information."

The IT-worker email was released as part of an almost 200-page document dump of interview summaries from the FBI's investigation into Clinton's use of a private email server.

The Trump campaign on Friday seized on the IT worker's comments.

“The fact an IT staffer maintaining Clinton’s secret server called a new retention policy designed to delete emails after 60 days a 'Hillary coverup operation' suggests there was a concerted effort to systematically destroy potentially incriminating information," Jason Miller, senior communications adviser to Trump, said in a Friday statement.