A Central Industrial Security Force (CISF) head constable posted at the NTPC administrative building in Mushidabad’s Farakka reportedly shot himself with his service revolver early on Sunday while on duty.

Ramkumar Singh, 48, was from Baroani village in Bihar’s Begusarai.

“Around 4am, his colleagues heard a firearm going off and found Singh lifeless at his post,” said a CISF source.

"He had no prior disciplinary issue or work-related strife. We suspect a family issue drove him to suicide,” the source added.

Singh was rushed by colleagues to the NTPC hospital and declared dead on arrival.

CISF officials declined to comment officially.

But sources on condition of anonymity said Singh had taken a month-and-a-half leave in late April and “seemed different” on rejoining duty.

“He seemed depressed,” said a colleague.

Jangipur police said prima facie the driving factor was “personal”, “not professional’.

The body has been handed over to the family after post-mortem.

Depression-related factors are probable," said superintendent of police (Jangipur), Bholanath Pandey.

Singh is survived by a wife and two adult sons.