EXCLUSIVE: A source close to James Comey tells Fox News the former FBI director’s Senate testimony has been “closely coordinated” with Robert Mueller, whom the Justice Department appointed as special counsel to oversee the Russia investigation.

Comey’s written opening statement for his Senate Intelligence Committee appearance was released Wednesday afternoon. Fox News is told that statement and subsequent testimony during Thursday’s question-and-answer session has been discussed with former FBI Director Mueller.

Fox News has reported that Comey and Mueller recently were in contact, but this speaks to the extent of the coordination regarding Comey’s closely watched hearing appearance.

The source also told Fox News that, as can be seen in Comey’s opening statement, the fired FBI director will not come to any legal conclusions about whether there was “obstruction of justice” on the part of President Trump.

Rather, he will just lay out the facts surrounding his interactions with the president.

By contrast, Comey did make a legal judgment on whether he thought Hillary Clinton should have been charged in the email scandal during the 2016 presidential election campaign. In a July press conference, Comey said the 2016 Democratic presidential nominee had been “extremely careless,” but her conduct did not rise to the level of criminal charges.

Legal experts tell Fox News it is not uncommon for investigators, such as a special counsel, to be in contact with someone who is a party to their investigation.

"It would be unheard of for a prosecutor to allow his star witness to testify before Congress without heavy coordination," said Fox News senior judicial analyst Judge Andrew Napolitano.