The decomposed body of a 52-year-old doctor at RG Kar Medical College and Hospital was found on Sunday afternoon in a two-storeyed house that he had rented in Lalgarh, Dum Dum, five months ago.

Neighbours of the deceased, Goutam Pal, a professor of medicine at RG Kar Medical College, alerted the police after getting a stench from the house where he lived alone. The cops broke open the main door, which was bolted from inside, and found the body on a bed in a room on the first floor.

Doctors who examined the body told the police that Pal had died at least three days ago. The cause of death is yet to be ascertained.

The police said no suicide note was found in the house. The bed on which the body was found was in perfect condition, leading to the suspicion that Pal might have suffered a cardiac arrest.

The contents of Pal's stomach have been preserved to test for traces of poison.

"Since the door was bolted from inside, involvement of an outsider can be ruled out. We will have to wait for the post-mortem report to know whether the deceased had committed suicide or had died of a natural cause," said an officer of Dum Dum police station.

Pal was constructing a two-storey house in the Lalgarh colony, 1.7km from Dum Dum railway station, and had rented a house in the same locality last June to supervise the work.

"We used to see him leaving the house in the morning and returning in the evening. He used to keep to himself and hardly interacted with neighbours. We never saw any family member visiting him," said Shukla Mandal, a neighbour.

Suddhadhan Batabyal, principal, RG Kar Medical College and Hospital, said Pal had not taken a class since Friday. "He was supposed to see patients in the outpatients department but remained absent. We called him repeatedly on his cell phone but no one picked up," Batabyal said.

On Sunday, when Batabyal called the doctor's cell phone again, Pal's daughter answered the phone and told him that her father's body had been found in his home.