The Justice Department's inspector general has opened an investigation into whether former FBI Director James Comey leaked classified information when he sent memos to a friend of his outside of government that were then sent to reporters.

The Wall Street Journal reported that before sending the memos, Comey removed information that he knew was classified. But when he left, the FBI upgraded some additional information to classified, and the IG is now reviewing the memos.

Comey gave his friend Daniel Richman, a former federal prosecutor who is now a law professor, four memos, people familiar with the situation said. At the time, only one contained information considered to be classified.

Last year, while testifying before Congress, Comey told lawmakers that he gave the memos to a friend to share with media because he didn’t want to do it himself.

“My judgment was, I need to get that out into the public square,” Comey said during his hearing last year. “I asked a friend of mine to share the content of the memo with a reporter. Didn’t do it myself for a variety of reasons. I asked him to because I thought that might prompt the appointment of a special counsel.”

The memos were given to Congress this week.

President Trump late Thursday tweeted that the Comey memos show he may have leaked classified information.

