A company with ties to Cowboys QB Tony Romo and organized to put on a fantasy football event in Las Vegas has filed a lawsuit against the NFL, asking for more than $1 million in damages.

Fan Expo LLC sued the league in Dallas on Monday, accusing the NFL of illegally interfering with its National Fantasy Football Convention that was supposed to take place earlier this month.

Tony Romo isn't happy with the NFL's role in the cancellation of his National Fantasy Football Convention, and the company that was supposed to put on the event is suing the league for damages. Ronald C. Modra/Sports Imagery/Getty Images

The event, which was a partnership between Romo and a Dallas entrepreneur, was supposed to take place from July 10-12 at a convention area of The Venetian and feature a roster of at least 60 NFL players under contract, including Romo, Odell Beckham Jr., Rob Gronkowski and Dez Bryant. But five weeks before the event, the suit alleges, NFL officials called people associated with the players who were getting paid to come -- their teams, families, their agents and, in some cases, even their parents -- to tell them they would be fined or suspended if they attended the convention.

The NFL also told the NFL Network's Michael Fabiano that if he remained the host of the event he would risk losing his job, the suit claims.

The NFL's gambling policy states that the league does not allow participating in any appearances that are held or sponsored by a gambling-related establishment. But Fan Expo LLC argues that its three-day event wasn't in violation of that policy.

Although the convention center was owned by Sands, which owns The Venetian and The Palazzo, the expo where the convention was to take place doesn't have gambling and wasn't sponsored by a casino. There was some confusion about this because the original materials said the event was at The Venetian itself.

The suit argues that the NFL's gambling policy gets more complicated when considering that the New Orleans Saints had a training camp last year on the site of a resort that has a 103,000-square-foot casino and that the Detroit Lions recently got a big sponsorship from MGM Grand Detroit.

"If we had known about the issue of the place or thought that was something that could've been an issue, the NFL could have told us right away," Romo said on ESPN's The Herd with Colin Cowherd. "The NFL never called me or my agency or the NFFC."

The event was canceled, and Fan Expo said it had to refund money to everyone associated with the event.

Officials with Fan Expo said they would have no comment on the suit, while NFL spokesman Brian McCarthy said the league was unaware that a suit had been filed against it.