A group of men posing as CBI officers raided a businessman's house in the Bhowanipore area of the city and allegedly looted Rs 30 lakh and jewellery, police said.

According to the complaint lodged by 60-year-old Suresh Wadhwa at Bhowanipore police station, a group of 7-8 men posing as CBI officers barged into his residence on Rupchand Mukherjee lane at around 8 am on Monday and started what they said was a "raid".

"The men arrived in three vehicles having police stickers pasted on them. I opened the door and they barged in telling me that they are CBI officers. I had asked them to show their identity cards, but they did not bother," Wadhwa said when contacted.

The businessman claimed that the men left with Rs 30 lakh and jewellery worth another several lakh and told him that the "seizure list" would be sent to him sometime later.

"They had prepared a seizure list at my residence but told me that they will send it later. They even told me that I will be summoned by them to their office later," Wadha said.

Calcutta Police have started an investigation after the businessman lodged a complaint.

Sleuths of Kolkata Police's detective department along with their colleagues from Bhowanipore Police Station have started a probe into the "crime", a senior police officer said.

Initial probe revealed that the men were tall and well-built and they were carrying "lathis" during the "operation" at Wadhwa's residence.

Detectives are suspecting the role of insiders or people who are close to the Wadhwa family in the crime, the officer said.

"We are talking to the servants at Wadhwa residence and others who are employed with their farm. These culprits had details of the Wadhwa household, where the cash and jewellery were kept," the police officer said.

"We are collecting CCTV footage from the locality to spot the three vehicles used in the crime", the officer said.