The National Football League Players Association (NFLPA) has filed a federal lawsuit against the league and its owners, alleging that the owners conspired to set a “secret salary cap” for the year of 2010, according to reports.

According to ESPN the players union will attempt to prove that the league’s owner colluded to establish a $123 million salary cap in 2010 despite the fact that players were under the impression that the 2010 season was supposed to be an uncapped year.

“Our union recently learned that there was a secret salary cap agreement in an uncapped year,” NFLPA President Domonique Foxworth told reporters May 23. “The complaint today is our effort to fulfill our duty to every NFL player. They deserve to know, above all, the facts and the truth about this conspiracy

According to ESPN, the players union filed its complaint May 23 in the U.S. District Court in Minneapolis, claiming the suit falls under the supervision and oversight of Judge David Doty. Doty presided over litigation brought by former NFL player Reggie White in 1993 that challenged NFL labor policies. Settlement of White’s case led to a collective bargaining agreement (CBA) between the players and owners that lasted from 1993 to 2010.

Under that former CBA, 2010 was originally designated as an uncapped year, where teams would not be limited on how much money they could spend towards the payroll for signing players.

However, in 2012, the NFL announced that four teams—Washington Redskins, Dallas Cowboys, Oakland Raiders and New Orleans Saints–had violated a “secret salary cap,” giving them an “unfair advantage” over other teams that did not surpass the $123 million mark in payroll for players. Those four teams were penalized by losing money for their payroll for the 2012 and 2013 seasons; the money lost would then be redistributed towards the payrolls of the other teams of the league.

“The league expressed their view that they thought those teams had gotten a competitive advantage,” NFLPA outside counsel Jeffrey Kessler told reporters. “If we wanted other salary cap increases for the clubs … the price for doing that was doing this salary cap reallocation. Had the union known about prior collusion, the union would never have agreed to these cap reallocations.”

ESPN reported the players union seeks $1 billion in damages for free agent players of 2010, but NFL spokesman Greg Aiello told reporters that the NFLPA’s claim has no legal merit and will be dismissed.

“The filing of these claims is prohibited by the collective bargaining agreement and separately by an agreement signed by the players’ attorneys last August. The claims have absolutely no merit and we fully expect them to be dismissed,” Aiello said. “On multiple occasions, the players and their representatives specifically dismissed all claims, known or unknown, whether pending or not, regarding alleged violations of the 2006 CBA and the related settlement agreement. We continue to look forward to focusing on the future of the game rather than grievances of a prior era that have already been resolved.”

Gary Roberts, dean of Indiana University’s School of Law, told the Associated Press that Aiello may be right.

“The union’s problem is not in the merits of their argument, it’s in the procedural part of it. They signed a CBA that said all litigations are settled,” Roberts said. “What they’re saying now is that only applied to things that ‘we were aware of. We only waived and settled all claims that we knew existed. We couldn’t be asked to waive any claims that we did not know existed.’ “