Tulsa police have announced that they are investigating an incident that occurred Friday night, after an off-duty Sheriff's officer heckled NASCAR star Tony Stewart, and the driver climbed into the stands to confront him.

The confrontation happened Friday night, during the 'Chili Bowl', a dirt-track racing event that was held at the Tulsa Expo Center. The Tulsa County Sheriff's Office says the heckler was Corporal Kyle Hess, an officer with the sheriff's office. The Sheriff's department also announced that an investigation into the incident has been launched.

Stewart was not competing at the Chili Bowl Nationals, which has more than 300 drivers competing in midget car races. He was there to help with track preparations, something he did last year. Earlier this week, Stewart said in a press conference there that he plans to return to racing in dirt events when he retires from driving in the Sprint Cup Series after this season.

Confrontation is nothing new to Stewart. While many of the driver's altercations in the past have happened with fellow competitors, he did have an incident five years ago that saw Stewart held for questioning after he was accused of tossing his helmet at a track co-owner in Ausralia, after arguing about track conditions. Stewart was not charged. USAC fined Stewart $10,000 and placed him on probation for the rest of the year after a July 2008 incident at Lucas Oil Raceway where he was accused of knocking a headset off an official and shoving another in a dispute. Stewart later apologized for his actions.