RICHMOND, Va. (WVIR) - There are new developments in the corruption case against former Virginia governor Bob McDonnell.

The prosecution's key witness against McDonnell is now facing fraud allegations of his own.

“I never promised - and Mr. Williams and his company never received - any government benefit of any kind from me of my administration,” McDonnell said.

Jonnie Williams, former CEO of Star Scientific, is expected to be a lead witness in the prosecution's case against McDonnell.

“[Williams] is probably going to be one of their star witnesses if not the star witness,” Kyle McNew of Michie Hamlett Law Firm said.

Williams is expected to testify that McDonnell promised to promote Star Scientific in exchange for gifts from Williams.

However, a new class action lawsuit brought by consumers of Star Scientific Supplements is calling Williams' credibility into question.

The lawsuit alleges Williams' company made false claims about its supplements

“It was touted of treating all of these ailments, multiple sclerosis, Alzheimer’s, and in fact it had no positive health benefits at all,” McNew said.

He says McDonnell's attorneys will try to rely on these claims to portray Williams as someone a jury shouldn't believe.

“In situations where he has a duty to tell the truth does he do that,” McNew said. “He has a duty to tell the truth to investors. There are duties to tell the truth to purchasers of products. If you don't tell the truth in those contacts, are you telling the truth on the stand?”

McNew says claims made in this civil suit may tip the scale.

“It could lead a jury to believe this is someone who will say anything to advance his personal situation, whether that is true or not doesn't matter. It is what the jury's perception is.”

It only takes one juror to find the former governor not guilty of the charges he faces.

Williams may have one strike against him when the jury learns he was granted immunity from the prosecution.

McDonnell's trial is scheduled to begin in July.