Two off-duty Queens cops fatally beat a Long Island man with a baseball bat after he allegedly rear-ended their car last month, his widow claims in court papers.

The medical examiner has ruled that Michael J. Murphy’s death on April 10 was a homicide due to complications from a blunt impact to his head. The report did not say what caused the injury. He died eight days after scuffling with cops.

Murphy’s wife, Alane Avallone, said the officers “repeatedly struck [Murphy] . . . with a baseball bat,” rendering him unconscious. But police insist that Murphy, 53, of East Meadow, was the one who went on the attack after he plowed into a car carrying the two cops on April 2 in Forest Hills.

Both cops remain on duty. The incident is being investigated by the Internal Affairs Bureau.