12 Kolkata: A 72-year-old woman and her husband, both former professors, residing in Baisnabghata Patuli Township, have become victims of the biggest ‘digital arrest' fraud reported this year, losing Rs 2.4 crore to scammers. Posing as CBI officials, the fraudsters accused the victims of being involved in money laundering and put them under ‘digital arrest' for 12 days, during which they transferred money to the crooks from four bank accounts. The couple has now lodged an FIR with Patuli police detailing the bank transactions that took place between June 6 and June 17. According to the complaint, the couple received a call on June 4 from an unknown number. "The person at the other end claimed he was a senior CBI officer. More joined in and they threatened us saying we were involved in money laundering. They said they were placing us under digital arrest till we returned the cheated amount of money. Subsequently, from June 6-17, in phases, my husband and I were coerced into transferring a total of Rs 2,36,38,000 from our personal accounts to unknown individuals' accounts," the complaint states. A case has been registered under BNS sections pertaining to cheating and criminal conspiracy. The detective department is likely to assist in the probe, senior officers at Lalbazar said. When contacted by TOI, one of the victims said, "We are already under extreme trauma. Do not try to contact us again." An investigating officer said the scammers coerced the victims into transferring funds through multiple RTGS transactions from their accounts in two public sector banks. Officers from Patuli police station and cyber cell of South Suburban Division are now trying to freeze the recipient accounts and track the digital footprint of the scammers. The case follows a pattern of similar frauds targeting senior citizens over the past year and half. A combination of reasons, including unfamiliarity with the digital world and emotional vulnerability of the elderly, are factors behind the overwhelming number of senior citizens falling prey to cyber frauds, say senior police officers. The fact that many of them stay alone with no youngsters at home for long periods make them vulnerable to blackmail and threats by cyber crooks. According to another officer, older adults are targeted because they are more likely to respond to communications from legitimate-looking sources such as a bank, police or a govt department. "Research suggests this relates to a greater generational trust in authority. Besides, older people are more likely to live alone and have smaller social networks. This reduces opportunities to discuss potential scams and seek advice from others when they have concerns or doubts about the legitimacy of online requests," he claimed.