A case was registered after the recovery of charas and drug pills in the high-security Arthur Road Jail in Mumbai, police said on Tuesday.
A police official said 134 grams of Charas and half a dozen drug pills were found stuffed in polythene near one of the barracks where prisoners arrested in sensitive cases are lodged.
The drugs were spotted by a jail constable on November 30. An FIR was registered on Sunday.
Police suspect that someone had thrown the bag from outside.
The bag was found lying near barrack number 11 which houses undertrials in sensitive cases.
Police will check CCTV footage of the area, the official added.
