Pandurang Martand, who hails from Chichondi village in Nilanga tehsil of the district, was allegedly assaulted by head constable Namdeo Koli at a state transport bus depot, an official said.
Mr Koli (58) punched Martand, a farmer by profession, with his hands and feet, leaving him injured. The victim went home after the incident and was under medical treatment, he said.
What triggered the assault was not yet known, the official added.
On March 12, he succumbed to injuries, his son Ram Martand (30) said in a complaint lodged with the police in the district, around 500km from Mumbai.
"Based on the complaint we registered an accidental death case at the Aurad Police Station. We are investigating whether Martand's death was caused due to the attack," another senior police official said.