A star witness from the Charbonneau Commission has written a tell-all book.

In The Witness, Lino Zambito makes allegations that UPAC is too close to the Quebec Liberal Party.

Zambito was a co-operative witness for the commission, and repeatedly met with investigators over a four-year span.

“UPAC is supposed to be independent and lately from information that I got and things I saw, there's a communication between the head of UPAC and the office of the PMO which is a big, big problem,” he saidl.

He said that he noticed many investigations that dropped by the wayside and he believes that was because they came too close to the premier's office.

Premier Philippe Couillard flatly denied the allegation in Question Period.

“Never, ever, has there been any communication between my office and the police about an investigation,” he said.

Public Security Minister Martin Coiteux said that suggestion was completely false.

"The allegations on the relationship between the cabinet and UPAC is not true," said Coiteux.

Opposition leaders said the allegations are troubling.

“We have to be cautious, but at the same time, it's only adding another witness saying exactly the same,” said CAQ Leader François Legault.

Zambito also said he believes that UPAC has enough evidence collected to make arrests in other cases.

Parti Quebecois Leader Jean-Francois Lisée leaped at the opportunity to reiterate what will be his main reason for the next two years.

"We have another layer of allegations about shenanigans between the Liberal cabinet and police. The only remedy is for the Liberal government to go away," said Lisée.

Zambito is a former entrepreneur who testified for eight days at the Charbonneau Commission.

He pleaded guilty to fraud and was sentenced to two years house arrest and 240 hours of community service.

In his book (Le Temoin) he goes into more details about his involvement with several political players and construction companies.

“To put the facts down, so the population and the media know exactly what I gave UPAC,” he said.

He said he collaborated with UPAC and flagged former Liberal Party fundraiser Marc Bibeau.

“He had a lot of influence within the Liberal party and all the information I gave them is pointing towards that. They have as much as they had for Normandeau, to accuse her, but they're not accusing Bibeau,” he said.