Former NRL player Craig Field has been charged with murder after a man he allegedly assaulted on the NSW north coast died in hospital, police say.

Kelvin Kane, 50, was found unconscious outside the Kingscliff Beach Hotel on Marine Parade, Kingscliff, by police and paramedics about 9.15pm yesterday. Police allege that he had been punched on the head before falling to the ground.

Mr Kane was given cardiopulmonary resuscitation and taken to Tweed Heads Hospital, where he remained in a critical condition this morning, a hospital spokesman said. He was placed on life support but died this afternoon, Tweed Heads Local Court was told.

Shaun Fathers, 41, and Field, 39, were arrested at a Kingscliff home and taken to Tweed Heads police station, where they were charged with assault occasioning grievous bodily harm this morning before Mr Kane's death, police said.