WBA heavyweight champion John Ruiz is suing promoter Don King, saying the promoter is blocking a bout with Mike Tyson.

King is already being sued by Tyson, and has counter-sued.

Ruiz claimed King is trying to get Tyson to drop his action using a potential match-up between the two fighters.

The WBA champion said in the lawsuit that King told him and a lawyer that they were "traitors" if they did not let King use the fight in this way.

Ruiz also claimed that the fight would be the most lucrative of his career.

"Tyson has a proven, indeed unique, ability to generate box office interest, and thereby revenues," the lawsuit said.