Political operative Roger Stone met with a Russian national, who called himself Henry Greenberg and claimed to have damaging information about Hillary Clinton, in May 2016 in Florida, reports the Washington Post.

Why it matters: It's a meeting Stone did not disclose to congressional investigators when they met with him last year, and the interaction is now on Special Counsel Robert Mueller's radar.

The details:

During the meeting, Greenberg said he wanted $2 million in exchange for the information — which he did not share — and Stone rejected the offer, Stone told the Post in an interview.

Greenberg said he wanted $2 million in exchange for the information — which he did not share — and Stone rejected the offer, Stone told the Post in an interview. After the meeting, Stone exchanged text messages with former Trump campaign adviser Michael Caputo, who asked him "Anything at all interesting?" Stone replied: "No."

As Trump rails against FBI bias against his campaign, though the Justice Department's inspector general concluded that political biases did not impact the FBI's work in the Hillary Clinton email investigation, "Stone and Caputo ... now say they believe they were the targets of a setup by U.S. law enforcement officials hostile to Trump," per the Post.

"They cite records — independently examined by The Post — showing that the man who approached Stone is actually a Russian national who has claimed to work as an FBI informant."

— independently examined by The Post — showing that the man who approached Stone is actually a Russian national who has claimed to work as an FBI informant." Yes, but: "There is no evidence that Greenberg was working with the FBI in his interactions with Stone, and in his court filing, Greenberg said that he had stopped his FBI cooperation sometime after 2013." A spokesperson for the FBI declined to comment to the Post.

Go deeper: Timeline: Every big move by Mueller.