Underworld don Chhota Rajan was taken to AIIMS for medical surgery, prison officials said on Friday.
The officials said he was taken to AIIMS on Thursday for a minor nose operation.
The surgery was advised by the doctors and he is likely to be brought back to Tihar Jail after his operation, said a senior prison officer.
He will be kept in the prison hospital under doctors’ observation.
Security has been tightened in and around the hospital as a precautionary measure. Meanwhile, hospital sources said that he is admitted in an old private ward under the ENT Department.