Gregg Jarrett, author of the best-selling book The Russia Hoax, said Wednesday on Fox & Friends that he believes Robert Mueller is pursuing obstruction of justice charges against the president because there is no collusion with Russia to be found.

He said that if Trump sits down for an interview with the special counsel, there's a chance Mueller will "twist the facts and contort the law" in order to perjure him.

"Mueller has demonstrated time and again he cannot be trusted to be fair and impartial," said Jarrett, a Fox News legal analyst.

A report by The New York Times revealed that White House Counsel Don McGahn willingly spoke with members of Mueller's team for more than 30 hours over the last nine months.

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Jarrett added that based on topics discussed between McGahn and the Mueller's team, it seems as though the special counsel is pursuing obstruction of justice charges against Trump. 

The Times report revealed that McGahn spoke of Trump's mindset leading up to the firing of former FBI Director James Comey, as well as how the president tried to get Attorney General Jeff Sessions to take over the Russia probe.

"I think [Mueller has] given up, there was no evidence of collusion to begin with," Jarrett said, adding that the FBI "violated their own regulations" to begin the investigation in 2016. 

Jarrett said that Mueller -- an "inferior" officer -- doesn't have the legal basis to question Trump about exercising his constitutional authority.

"Where is it written that you can question the president about a non-crime called collusion?" he asked.

Jarrett said nobody knows what evidence Mueller has on possible collusion, but believes if there was compelling evidence, it would have come out publicly by now. 

He said Mueller has a clear "conflict of interest" as a longtime friend and colleague of Comey, whose firing would be central to an obstruction case. 

"How is it fair to the president? Who is Mueller disposed to believe? His friend who was fired by Trump or Trump? It's an obvious answer," he argued.

Watch the discussion from Fox & Friends above.

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