Five people were arrested on Sunday for allegedly operating a betting racket on horse races.
The police said the gambling den was operated form a house at Sindhi Colony in Chembur.
The accused used to meet a house at the Sindhi Colony from where they used to bet on horse races. Acting on a tip-off, the police sent a decoy customer to the house to place a bet.
Once the decoy placed the bet, he signalled to the police, who raided the place and caught the five persons red-handed.
The police have recovered seven SIM cards which were obtained using fake documents, said a senior officer.