A group of men knocked at a Bright Street house early on Wednesday posing as cops and forced the resident at gunpoint to withdraw and give them Rs 10,000, police said.

The robbery occurred at an apartment on the third floor of a building (B 50 Bright Street) near Park Circus where the complainant, Mohammad Irshad, lives, the police said. He told the cops five to six men had knocked at his home around 3.30am.

“The men first introduced themselves as policemen and entered the flat early this morning. They then threatened him with a gun and demanded money. When the complainant said he did not have any money at home, they forced him to take his ATM card and accompany them to the closest kiosk to withdraw money and hand it over to them,” an officer in Lalbazar said.

The men then fled with money, Irshad has said in his complaint.

Irshad told the police he lived alone and that his family stayed outside Calcutta. He was taken aback when the men rang the doorbell and told him they were cops. So, he opened the door. The building has no guards, he has said in his complaint with Karaya police station.

Although Irshad initially believed what the men told him (that they were cops), he later identified at least one person whose face was covered as a man from the neighbourhood, the police said.

Later, based on the complaint, officers of Karaya police station started a case of kidnapping, dacoity, and impersonation of a government official and under sections of the arms act.

Based on his statement, cops could identify and arrest one person, Tofazzul Islam alias Bhutto from his Masjidbari lane home, the police said.

A search is on for the remaining members of the gang.

The money is still to be recovered, the police said on Wednesday evening.