Kolkata, August 27: The Cyber Cell of Kolkata Police has launched an investigation into an alleged SIM fraud network involving the creation and distribution of unauthorised “ghost SIM cards” to cybercriminals. Preliminary findings suggest that the network was linked to fraudulent financial transactions that caused losses of more than ₹1.10 crore to residents over a period of two months.
According to investigators, several Point of Sale (PoS) telecom vendors, distributors and employees of telecom stores allegedly entered into a criminal conspiracy on or before August 21 to misuse confidential customer information. The alleged operation involved the unauthorised use of customer documents, personal details and biometric information collected during routine telecom transactions.
Investigators suspect that the data was used to impersonate genuine subscribers and activate multiple SIM cards without their knowledge or authorisation. These SIM cards were allegedly supplied to cybercrime operators, who subsequently used them to conduct fraudulent financial transactions and other illegal activities.
Kolkata Police Probes Alleged Ghost SIM Network
The investigation is focused on determining how many allegedly unauthorised SIM cards were activated, who facilitated their issuance and which individuals or organised cybercrime groups ultimately received them.
Police are examining the telecom chain involved in SIM activation, including PoS vendors, distributors and employees of telecom stores who may have had access to customer information during legitimate registration and verification processes.
₹1.10 Crore Fraud Linked to Two SIM Fraud Modules
According to the preliminary investigation, two separate operational modules have emerged in connection with the alleged network.
One module is linked to suspicious transactions worth ₹83.10 lakh, while another involves transactions amounting to ₹26.30 lakh. Together, the transactions under investigation exceed ₹1.10 crore.
Police are examining bank accounts, mobile numbers, SIM activation records and telecom documentation to establish the complete financial and digital trail.
Investigators are also trying to determine whether the allegedly unauthorised SIM cards were used to access bank accounts, digital wallets or other financial services.
Customer Data and Biometrics Allegedly Misused for SIM Activation
The case has raised concerns over the security of telecom customer data and the potential misuse of information collected during SIM registration and verification.
Identity documents, personal details and biometric information are used during legitimate SIM activation, making such information potentially valuable to criminals if obtained or used without authorisation.
Investigators suspect that customer information may have been used to impersonate genuine subscribers and activate SIM cards without their knowledge.
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Unauthorised SIM cards can potentially provide criminals with access to communication channels used in financial and other cybercrimes.
Police are therefore examining whether the suspected numbers were subsequently used for activities such as banking fraud, OTP-based fraud, account takeover, mule-account operations or other forms of financial crime.
The investigation is not limited to identifying the fraudulent transactions. Officials are also examining the digital activity associated with the suspected mobile numbers to establish how the SIM cards were used after activation.
PoS Vendors and Telecom Employees Under Scanner
The Cyber Cell is examining PoS outlets and telecom distribution channels from where the allegedly unauthorised SIM cards were issued.
Investigators are trying to establish whether individual employees deliberately shared customer information or whether they were allegedly acting under instructions from a larger network.
The activities of the suspected SIM cards and the devices in which they were used are also being examined. These records could help investigators connect the alleged SIM suppliers with cybercrime operators involved in financial fraud.
SIM Activation Records and Financial Trails Being Analysed
Police are examining multiple layers of digital and financial evidence to establish the alleged chain of operations.
These may include:
- SIM activation and KYC records
- Customer identity and biometric verification records
- Mobile numbers linked to suspected SIM cards
- Device identifiers
- Call-detail records
- Bank account transactions
- Digital wallet activity
- Transfers involving suspected mule accounts
The movement of funds after the alleged fraudulent transactions could provide important clues about the beneficiaries and the wider network.
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Renowned cybercrime expert and former IPS officer Prof. Triveni Singh said that unauthorised SIM cards can become an important enabling layer for organised cybercrime networks.
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He said investigators should correlate SIM activation records, KYC documents, biometric verification, device identifiers, call-detail records and financial transactions to establish the complete chain.
According to Singh, identifying the final beneficiary alone may not be sufficient. The role of individuals or networks allegedly responsible for misusing identity data and facilitating the issuance of SIM cards should also be examined alongside the money trail and digital evidence.
Probe Examines Possible Wider Cybercrime Network
The investigation is also expected to establish whether the same network supplied SIM cards for multiple cybercrime operations across Kolkata or other locations.
Police are examining whether the suspected PoS and telecom distribution network was used repeatedly and whether the same customer information or activation channels were associated with multiple fraudulent transactions.
Establishing these links could help investigators determine whether the case involves isolated instances of misuse or a coordinated operation.
Kolkata Cyber Cell Traces Alleged SIM Fraud Chain
For now, the probe remains at an early stage. Kolkata Police is working to establish the complete structure of the alleged SIM fraud network, identify those involved and assess the total financial impact.
As investigators analyse telecom records, banking transactions and digital evidence, the probe is expected to shed more light on how the alleged “ghost SIM” network operated and how extensively the numbers were used in cybercrime.
About the author — Ananya Aradhya writes on cybercrime, fraud, scams, cybersecurity, digital safety, and emerging threats. Her work also covers major criminal cases, financial frauds, consumer scams, and stories that highlight risks affecting people in the real and digital world.
