U.S. police are gathering more testimony from the victim of an alleged sexual assault case involving President Park Geun-hye's now fired spokesman.

Washington D.C. police say they are trying to sort out if the alleged assault was limited to ex-spokesman Yoon Chang-jung grabbing the buttocks of a female intern hired by the South Korean Embassy in D.C. as she initially testified.

U.S. federal prosecutors are also investigating Yoon's case.

South Korean lawyers knowledgeable of U.S. criminal procedures say Yoon can't be directly investigated or questioned under U.S. law unless there is clear evidence a crime was committed.