LAS VEGAS » Mixed martial arts fighter Georges St-Pierre could be disciplined by Nevada athletic regulators after his corner illegally applied petroleum jelly to his body during his Ultimate Fighting Championship title fight against B.J. Penn of Hawaii last week.

Keith Kizer, executive director of the Nevada State Athletic Commission, said yesterday that he entered the ring after the second round of Saturday's welterweight championship fight to instruct the fighter's cornerman to stop putting jelly on St-Pierre's shoulders and upper back.

Kizer said he and a fight inspector for the commission made St-Pierre's cornermen wipe the jelly from his body.

Under UFC rules, petroleum jelly may be used on a fighter's face, but not elsewhere.

Kizer said he's not sure whether the jelly affected the outcome of the fight, but said officials are concerned about whether it could have prevented Penn from performing certain grappling moves.

A doctor stopped the fight after the fourth round after St-Pierre battered Penn.

The Penn family declined comment on the advice of their lawyer, Raffi Nahabedian, who told the Associated Press that Penn, a lightweight from Hilo who relies on grappling to submit opponents using Brazilian jiujitsu, wants a rematch because he believes St-Pierre had the jelly on his body to prevent attempts to grasp him.

“;If a ground and pounder can get away with neutralization of a jiujitsu person's game, ... the sport is fundamentally corrupt and it cannot be considered a fair fight,”; Nahabedian said.

Penn's lawyer sent a letter this week, asking the commission to look into the use of the slippery substance. Kizer said the commission forwarded a copy to St-Pierre and asked him to respond within 20 days.

UFC president Dana White was not available for comment because he was traveling, a league spokeswoman said.

St-Pierre's manager Shari Spencer said the Canadian fighter was not cheating, and that the cornerman who applied the jelly accidentally got some on St-Pierre's body while rubbing him during a breathing exercise between rounds.

Spencer said St-Pierre was cooperating fully with the athletic commission and was willing to fight Penn again anytime.

Kizer said the Nevada commission would likely make a decision at its March meeting, after St-Pierre has responded.

Kizer said disciplinary possibilities include a warning, fines or suspension.