The raids were conducted in Uttar Pradesh's Noida and Kerala's Changaramukulam on Thursday

NEW DELHI: The Mumbai Police in a joint operation with the Military Intelligence of Jammu and Kashmir have busted two illegal VoIP exchanges and SIM boxes that were used to seek information from the defence personnel, and it is suspected that Pakistan's secret service agency, the ISI, was involved.

The raids were conducted in Uttar Pradesh's Noida and Kerala's Changaramukulam on Thursday.

Army sources said two functional SIM boxes were recovered with 100 slots each and approximate 200 SIM cards, along with two routers, three modems, antennas, batteries and connectors, from Noida and Changaramukulam. Primary information about the drive was being obtained, sources said.

During the raid, one accused was arrested from Changermakulam.

In September 2019, defence persons received calls from suspicious numbers, seeking information related to important defence installations. The callers posed fictitious identity, and the involvement of the ISI was suspected.

Further investigation by the Military intelligence and Mumbai Police revealed few illegal VoIP exchanges in Uttar Pradesh and Kerala, which routed calls incoming from Pakistan to local numbers. These were then used to extract information from the Defence persons. Based on this information, the Mumbai Police carried out joint operation with the Military intelligence.

The exchanges, which converted international voice calls originating from Pakistan into local GSM calls, used the Chinese SIM Boxes (boxes fitted with GSM SIM cards of local cellular service providers). These SIM boxes also used dynamic IMEI system, which made them difficult to be tracked. This system has been declared illegal by the Telecom Regulatory Authority of India.

As the Indian systems cannot control the calls generated in such systems, they are used for anti-national activities, sources said. Therefore, the Department of Telecommunications is not permitted to transmit international VoIP calls through the normal telephone network. The SIM box methodology is a financial fraud to the Government of India as well as to the mobile companies, sources said.

Investigations so far have revealed that the busted exchanges caused revenue losses in crores of rupees to the country's telecom department. Subsequent probe had then revealed that those exchanges were being used by hostile intelligence agencies to seek military information through calls and posed security threat to nation.

After the preliminary inquiry and the confirmation of the usage of unauthorised SIM box, the Dongri police station in Maharashtra's Thane registered the crime under sections 419, 420, 465, 468, 471, 120 (b) of the Indian Penal Code (IPC) with the clause 1 of the Indian Telegraph Act 1885, Sections 4, 20, 25, with section 3, 6 the Indian Wireless Telegraphy Act 1933, and forwarded the investigation to the crime branch.

The probe was underway to ascertain the identity of more individuals, suspected to be involved and locations of other similar exchanges. More arrests are likely to be made in this connection, as they might also be linked to compromising India's internal security, army sources said.