The source also said that P Chidambaram answered over 400 questions during his custody since August 21.
The 73-year-old Congress leader was arrested on August 21 and produced before the court the next day; since then he is in the CBI custody.
Special CBI Judge Ajay Kumar Kuhar accepted the CBI’s demand that Chidambaram needs to be confronted with other co-accused in the case.
Meanwhile. the former Union minister Chidambaram was on Monday produced before a Delhi Court on expiry of his four-day CBI custody.
Chidambaram's plea challenging his custody will come up for hearing on August 26 when his CBI custody gets over.
INX Media Ltd, which was owned by Mukerjea, had allegedly paid bribes to get a Foreign Investment Promotion Board approval, which was facilitated by ex finance minister P Chidambaram's son.
The six accused were arrested yesterday in connection with two separate FIRs registered by the CBI involving Modi and his uncle Mehul Choksi, the owner of Gitanjali Gems.