Four illegal telephone exchanges being operated from different apartments have been busted here in Maharashtra and four people arrested in this connection, a police official said today. The accused were illegally routing international calls through Voice Over Internet Protocol (VOIP), she said. Acting on a tip-off, a police team raided four apartments at a building in Mumbra area yesterday and seized electrical equipment worth Rs 14 lakh from there, Thane police spokesperson Sukhada Narkar said.

The police also seized several SIM cards of different companies, routers, and laptops from the flats, she said. International calls were being illegally routed via VOIP through local mobile numbers at these exchanges, she said. Such a set up of interconnecting Internet/VOIP and mobile connections is not permitted as per Indian telecom laws, the police said, adding that the preliminary loss to the national exchequer was being ascertained.