A court will overturn former national Security Adviser Michael Flynn's conviction for lying to the FBI, a House Judiciary Republican predicted Sunday.

The prognostication by Rep. Darrell Issa, R-Calif., who is retiring from Congress in January, comes after a federal judge demanded more information about Flynn's dealings with the FBI ahead of his expected sentencing on Tuesday. Last December, Flynn pleaded guilty as part of special counsel Robert Mueller's federal Russia inquiry to lying during a January 2017 interview with investigators. He told them he did not discuss sanctions with then-Russian Ambassador Sergey Kislyak. Flynn's lawyers have argued their client should not receive prison time due to the casual nature of the sit-down, including how Flynn was not advised he was under scrutiny from the government.

"I would not be surprised a bit if the conviction of Flynn is overturned because of the Justice Department and the FBI's misconduct," Issa told Fox News.

[Related: Mueller slams Michael Flynn for needing a warning not to lie to FBI]

Issa then criticized fired FBI Director James Comey, who last week said the bureau was able to question Flynn without following established procedures because the Trump White House was not as "organized" as previous administrations.

Mueller recommended earlier in December that U.S. District Judge Emmet Sullivan, the judge overseeing Flynn's case, not hand down a prison sentence to Flynn, a retired U.S. Army lieutenant general and 2016 Trump campaign surrogate, given his "substantial assistance" to the Russia probe.