A group of men, who allegedly posed as employees of a US-based company and duped American citizens by claiming that wrong transactions had occurred in their crypto wallets, were arrested on Wednesday.

Police raided a call centre on Roy Bahadur Road in Behala and arrested seven people who were allegedly involved in making voice over internet protocol (VoIP) calls to US citizens.

They would siphon off money from the bank accounts of the victims in the US in the name of resolving the issue of “incorrect transactions in their crypto wallet”.

The arrested persons have been identified as Ritick Singh, 25, Sohail Rayaz, 28,
Debasish Roy, 38, Gobind Rajhbhar, 28, Ritesh Raj, 25, Akash Shaw, 32 and Sujan Singha, 29.

Barring Ritesh, who hails from Bihar, the rest are residents of Calcutta, the police said.

“This group used to take control of the bank accounts of the victims with the help of a remote desktop application, posing as employees of the US-based company,” said a senior officer of the detective department of Kolkata Police.

The officer said the gang chose the clients carefully, identifying those dealing with cryptocurrencies.

Once selected, the callers from the Behala call centre would make their victims believe they had erred while making certain cryptocurrency transactions and that the issue could be resolved if they cooperated, the police officer said.

“They would tell the victims that the way to resolve the so-called snag in the transaction was to share the bank account details and the codes sent to their mobile numbers. This would give access to the bank accounts of the victims,” the officer said.

During the raid, the cops seized several laptops, iPhones and routers allegedly used to make the calls.

The police said tracing VoIP calls was difficult for the victims since IP addresses were used.

“Even the identities of the callers can be spoofed or disguised,” an officer said.

Tracking VoIP calls involves analysing complex networks and continuously decoding data, and requires specific skills. The gang was probably aware of this, the officer added.