Former finance minister P Chidambaram was referred to the All India Institute of Medical Sciences on Saturday after he complained of stomach pain.
Chidambaram is lodged in Tihar jail since September 5 in INX Media case.
Chidambaram’s judicial custody was extended by two more weeks till October 17.
The CBI had registered an FIR on May 15, 2017, alleging irregularities in the Foreign Investment Promotion Board (FIPB) clearance granted to the INX Media group for receiving overseas funds of Rs 305 crore in 2007 during Chidambaram's tenure as the finance minister.
Chidambaram, who was Union home minister as also finance minister during the UPA rule from 2004 to 2014, was arrested by the CBI on August 21 from his Jor Bagh residence.
(With agency inputs)