Kothari, who was called at the agency headquarters here for questioning, and Rahul were not cooperating in the investigation that led to their arrest, they said.

A consortium of seven nationalised banks has given bank loans worth Rs 2,919 crore from 2008 onwards Rotomac Global Pvt Limited from 2008 onwards, the CBI FIR has alleged.

The amount swelled to Rs 3,695 crore, including the accrued interest, because of repeated defaults on payment, the officials said.

The CBI has initiated the action on the complaint of Bank of Baroda, which was a member of consortium led by Bank of India, which had approached the agency fearing that Kothari may flee the country like Nirav Modi and his uncle Mehul Choksi.Meanwhile, the Income Tax Department has issued a show cause notice to the group stating as to why prosecution should not be launched against them for alleged tax evasion.

The principal exposure of the banks regarding the loan is Bank of India Rs 754.77 crore, Bank of Baroda Rs 456.63 crore, Overseas Bank of India Rs 771.07 crore, Union Bank of India Rs 458.95 crore, Allahabad Bank Rs 330.68 crore, Bank of Maharashtra 49.82 crore and Oriental Bank of Commerce Rs 97.47 crore, officials said.

The case against Rotomac Global Pvt Limited, director Vikram, his wife Sadhana, and Rahul and unidentified bank officials was filed on a complaint received from Bank of Baroda, they said.