MANKATO, Minn. – The NFL Players Association claims the Minnesota Vikings and Kansas City Chiefs may have engaged in collusion while negotiating contracts with their first-round draft picks.

The union claims the teams may have had illegal knowledge of the signing bonus offered to a player chosen after Kansas City selected Ryan Sims with the sixth pick, and Bryant McKinnie was picked seventh by Minnesota.

The players association says the teams subsequently offered the players a lower amount, so the union filed a request for an investigation on Monday with the NFL Management Council, ESPN.com first reported Tuesday.

”If two clubs take the same position [on offers to their players], then one player can’t say, ‘Look, No. 7 signed for this or that amount, so I should get a few bucks more,”’ said Richard Berthelsen, an attorney for the players association.

Roy Williams, the No. 8 pick by Dallas, was offered the larger signing bonus, according to the union.

Berthelsen said a letter to the management council asks for information about any communication between the Chiefs and Vikings regarding negotiations with their top draft picks.

Rob Brzezinski, vice president of football operations for the Vikings, called the accusations ”ridiculous” and ”baseless.”

Carl Peterson, president and general manager of the Chiefs, also said the claims were baseless. He said Kansas City has never discussed contract talks with any teams.

”The only conversations that we ever have with other clubs is usually, ‘It’s too bad you can’t get your guy done, we’re struggling also,”’ he said. ”There’s been no discussions.”

Ben Dogra, an agent for McKinnie, did not immediately return a phone call Tuesday night from The Associated Press.