Roan Carneiro won the BattleGrounds MMA welterweight tournament with three wins on Friday night, but he has another battle to fight.

"Jucao," a UFC veteran who defeated Randall Wallace, Trey Huston and Brock Larson in Tulsa, Oklahoma, on Oct. 3, claims that the Oklahoma Athletic Commission "robbed" part of his $50,000 prize after his win over Larson.

"They robbed me, man," Carneiro told MMAFighting.com.

According to the American Top Team fighter, the commission fined him in $15,000 for arriving late to a physical exam. However, he claims that commission officials only told him about the fine after he won the $50,000 prize.

"They took 30 percent of my money," he said. "They said I was late for a physical after the weigh-ins, but I did everything they asked and was never late to anything. They never notified me."

"I heard they can only fine you up to $2,500 for any serious misconduct or if I’m late for anything," he said. "When the promotion paid me after the win, live and inside the cage, they already had discounted the 30 percent. I tried to contact the commission, but they had already left the arena. They didn’t even talk to me."

Carneiro will try to "dialogue with the commission" in order to get his money back.

"They said it was because he was an hour and half late for medical check. I thought that was excessive but it was out of our hands," Battlegrounds president Kenny Monday told MMA Fighting's Ariel Helwani."We told him he should try and appeal. Commission was very tight with rules especially tournament athletes. I think because of the tournament and all the pressure on them they were very sensitive.