Former FBI Director James Comey admitted to the Justice Department's inspector general that he initially forgot that Anthony Weiner was married to Hillary Clinton aide Huma Abedin, the IG said in a report on the FBI's investigation into Clinton's private email server.

In late 2016, the FBI realized that some of Clinton's emails made their way onto Abedin's laptop at home that she shared with her husband, Weiner.

Then-Deputy Director Andrew McCabe thought that discovery was a "big deal," in part because it may have showed how classified emails might have been sent to a private, non-government computer.

But Comey indicated it didn't register with him why this news would be important.

"Comey said that he recalled first learning about the additional emails on the Weiner laptop at some point in early October 2016, although he said it was possible this could have occurred in late September 2016," the IG report said.

"Comey told the OIG that this information 'didn't index' with him, which he attributed to the way the information was presented to him and the fact that, 'I don't know that I knew that [Weiner] was married to Huma Abedin at the time,'" the report said.

The report said later that when McCabe reminded Comey about the Weiner computer, Comey "did not initially recall that he had been previously notified about the Weiner laptop."

The report said it assessed whether the "Weiner laptop" was "deliberately placed on the back-burner... to protect Clinton," but found none.

Weiner is a former House lawmaker who stepped down after being caught up in a sexting scandal. The emails from Clinton were found during the investigation into Weiner's activities.