Charles Brignone, the 44-year-old man from Tarxien whose body was found lodged against a reef yesterday, died from propeller injuries, sources said.
The cause of death had been established by the autopsy, the same sources said.
The police confirmed they are looking for a boat that could have caused the injuries.
Mr Brignone was reported missing after he failed to return from a snorkelling trip on Sunday afternoon. A search was launched by the AFM but it was halted at night and resumed yesterday morning when his body was found but a joint AFM/Civil Protection Department team.
Mr Brignone was wearing a dark wetsuit and a weight belt. His float had been found on Sunday.