The police are currently investigating an incident involving Kiefer Sutherland, star of the TV series 24, at the Costume Institute Gala of Metropolitan Museum in New York Tuesday.
According to witnesses, the Canadian actor hit Jack McCollough, Proenza Schouler designer, after he knocked Brooke Shields to the ground.
Sutherland asked him to apologize to the actress, but McCollough refused and instead pushed Kiefer. The actor allegedly retaliated by headbutting him, injuring his nose.
Sutherland is currently on probation for his arrest and conviction in 2007 for driving under the influence. He spent 48 days in prison and may return to jail if police feel he has broken the conditions of his probation.