Ghosh, who is lodged at the Presidency Correctional Home, complained of breathlessness, muscle cramps, severe stomach pain and shivering following which jail doctors attended to him and described his condition as "very critical".
They suggested that be shifted immediately to a hospital, preferably state-run SSKM hospital, a senior jail official told PTI.
Ghosh is on hunger strike demanding the arrest of others who were involved in the scam.
The doctors arrived at around 12.45 AM but Ghosh did not cooperate with them, the official said.
However, IG (Prison) South Bengal K K Mukherjee told PTI today that the condition of Kunal Ghosh was "medically stable and he is presently lodged in the jail hospital".
When asked whether Ghosh had asked to be shifted to a private hospital, Mukherjee said they had not received any application from him in this regard.
