Kiefer Sutherland

Kiefer Sutherland's widely reported scrap with a fashion designer in New York City could violate the terms of his DUI probation in Los Angeles, a prosecutors' spokesman tells TVGuide.com.

New York police are investigating a complaint from designer Jack McCollough, who says Sutherland head-butted him at a party and who was spotted Wednesday with a cut on his nose. No charges have been filed, but New York's Daily News reported Wednesday that the actor will surrender in the next few weeks to face a third-degree assault charge.

"All we can say at this point is that he was the victim of a vicious, violent, unprovoked assault and that the matter is in the hands of the authorities," a rep for McCollough said in a statement to TVGuide.com, declining further comment.

Witnesses have said McCullough knocked Brooke Shields to the ground at an after-party for the Met Costume Institute Gala on Monday, and that Sutherland demanded McCullough apologize. McCullough pushed Sutherland, and the actor responded with a head-butt, the witnesses said.

Shields' rep told TMZ that "nothing happened to her," adding "Jack did nothing inappropriate. It's not clear what caused Kiefer to do what he did."

Sutherland is serving five years' probation, which started in December 2007, on a Los Angeles DUI charge. Committing a physical assault could be a violation of that probation, and prosecutors could seek a court hearing on the matter even without waiting for any assault charge to wind its way through the New York courts, said Frank Mateljan, a spokesman for the Los Angeles City Attorney's Office.

"The terms and conditions of DUI probations include the standard, obey all laws," Mateljan said. "We're waiting for the investigation to wrap up before we get involved and we inquire about more information."

Sutherland will see much more of New York this summer: A Fox rep says the new season of 24 will soon begin shooting there.

Representatives for Sutherland and Shields did not return calls for comment.

Additional reporting by Joyce Eng