Storm owner News Limited said an independent Deloitte probe had concluded that the club breached the cap by 3.17 million dollars (2.80 million US), considerably more than originally estimated by the National Rugby League (NRL).
"Our original suspicion was that there was an elaborate and well orchestrated deception by certain senior managers at the club, and that has been confirmed by the Deloitte report," News chief John Hartigan said.
"Is it fraud? That's something for the police to decide and we are referring the findings to them," he added.
Hartigan said the breaches, committed over a period of five years, were significantly worse than first suspected by the NRL.
The club was stripped of the 2007 and 2009 premiership titles, ordered to repay 1.1 million dollars in prize money and fined 500,000 dollars after it was found to have breached the cap. It is also playing for no points this season.
"The investigation has confirmed that while the penalties are extremely tough, they are warranted," Hartigan said.
Hartigan said the Storm had maintained a dual contract system under which star players including Billy Slater, Greg Inglis and Cameron Smith were guaranteed payments from third parties "well in excess" of their official contract salaries.
Payments took various forms including gifts of cars, flights, boats and rent vouchers, as well as "donations" or "consulting fees" paid to the club.
Hartigan cleared coach Craig Bellamy of knowledge of the breaches and said it was unclear whether the players were aware that third party payments were not disclosed to the NRL.
All players had refused to cooperate with the Deloitte investigation, he added.
Hartigan dropped four of the club's directors, including chairman Rob Moodie, for persevering with legal action against the NRL "despite the fact the club had engaged in wide-ranging and elaborate cheating".
"We do not believe the independent directors have shown sufficient willingness to resolve the most pressing issue facing the club, and that is to field a team next season that is under the salary cap," he said.
He said the entire episode would cost News Limited 14 million dollars.
Source: AFP Global Edition