Jared Leto was just questioned by cops at LAX after a friend he was traveling with allegedly slugged a photog in the face.
We're told Leto and his travel partner touched down in LA and were about to get in a car when the incident happened. It's unclear what led to the punch being thrown but we're told the photog had a bloody lip.
Law enforcement tells us they responded for a possible battery but once they had finished talking with everyone involved, including Jared -- they determined no arrest was needed.
We're told Leto's friend shook hands with the pap and both went on their way.