The co-owners of a south Calcutta jewellery store accused of cheating customers of Rs 17 crore had locked themselves up in almirahs when police reached a New Alipore address on Wednesday night to arrest them.

Arjun Sen and sons Anirudha and Anirban, who jointly own Senco Jewellery Palace Abhushan Pvt Ltd on 118 Rashbehari Avenue - the store's name resembles that of a reputable jewellery chain - wouldn't come out of their makeshift bunkers until the cops threatened to prise open the almirahs, an officer said.

A fourth accused, Anirudha and Anirban's sibling, is absconding.

Arjun and his sons had allegedly misguided customers into investing in two financial schemes called Dhanbriddhi and Swarnatrisha that promised assured returns either in cash or gold on maturity.

Investigators suspect the accused misused the name "Senco" to lure customers. They have been booked under different penal provisions pertaining to cheating, criminal breach of trust and criminal conspiracy, which if proved could invite a maximum punishment of seven years in jail.

Arjun and sons Anirudha and Anirban had been allegedly hiding in their relative's home at 10 Kailash Pandit Lane in New Alipore for a month after the police started investigating complaints against them.

Sources said sleuths posted outside the New Alipore address spotted the trio entering the house on Wednesday evening. An hour later, they rang the bell and were told by the person who opened the door that Arjun and his sons were not home.

The sleuths searched the house but didn't find any trace of the trio until all but the three almirahs remained to be checked. "What raised our suspicion is that the family members who were around kept ignoring requests to show us what was inside the almirahs. The keys were brought when we threatened to break them," said an officer at Tollygunge police station.

All three almirahs - one wooden and two made of steel - were in the same room.

The arrests were on the basis of a complaint lodged at Tollygunge police station by a Jadavpur resident last month.

Sources said that apart from this one complaint, Tollygunge police station had received at least 300 petitions from people allegedly duped by the Sens. Half a dozen complaints have been lodged at other police stations, including Park Street, Bhowanipore, Ultadanga and Chandernagore in Hooghly district.

The Sen family's jewellery store on Rashbehari Avenue, near Lake market, and a costume jewellery business called Zaywar Jewelmart Pvt Ltd, located next to their flagship store, have been shut for a few weeks since investors started protesting outside the outlet.

Investigators said the accused may have made at least 3,000 customers invest around Rs 17 crore since 2012.

The arrested trio have been remanded in police custody for 10 days.