"He (Mitra) has been intimated to appear for questioning Thursday," a CBI official said.
After undergoing treatment at a private hospital, Mitra Nov 20 got himself admitted to the state-run SSKM Hospital from where he was discharged Nov 26.
Denying any involvement in the scam, the minister, upon discharge from the hospital, had asserted he would cooperate with the CBI whenever the agency called him for questioning.
The agency had earlier grilled Mitra's former confidential assistant Bapi Karim.
A few Trinamool leaders including Rajya Sabha members Kunal Ghosh and Srinjoy Bose are behind bars in connection with the scam.