A director of the Rural Electrification Board (REB) was found dead in a guest-house in the district town's Topshindaga on Thursday noon.
The deceased was identified as Ariful Alam, 52, son of Jamshed Hossain, from Rajshahi.
Azmal Huda, officer-in-charge of Kotwali Police Station, said that Ariful arrived in Jessore on Wednesday afternoon and put up at the REB guest-house for the night.
As the guest-house staff saw or heard no sign of him, and found his room locked till Thursday noon, they informed police.
Later, police recovered the body breaking the door of the room and sent it to Jessore 250-bed hospital for an autopsy.
However, the body bore no injury marks, leading doctors to primarily suspect he died of a heart attack.