Ranjit Pal and three other personnel of Kotwali police station went to Panisala village in Cooch Behar-I block for routine patrolling on the night of Kali Puja.
There they found a gang of gamblers and tried to take action against them at about 9 PM, the officials said.
The gamblers threw stones at the police team injuring two of them. When they were brought to a hospital, doctors declared Pal dead on arrival.
When contacted, district Superintendent of Police Rajesh Kumar Yadav, said the doctors told him that the injured sub-inspector died of cardiac arrest.
The other injured constable was hospitalised.
No one was arrested till late night.