The Kotharis allegedly owes Rs 3,695 crore to Allahabad Bank, Bank of India, Bank of Baroda, Bank of Maharashtra, Indian Overseas Bank, Oriental Bank of Commerce and Union Bank of India.
The Kotharis were questioned for the fourth consecutive day since the CBI filed the case against him and his family, and raided their residential and office premises in Kanpur in Uttar Pradesh.
Vikram Kothari has denied any wrongdoing. "Yes, I took a loan from the bank but it's wrong information that I haven't paid," he had said.
The CBI had filed case on Sunday night after getting a complaint against Vikram Kothari, his wife Sadhana and son Rahul, from the Bank of Baroda. Mr Kothari is the Chairman and Managing Director of Rotomac while his wife and son are Directors.
The Rotomac case coincides with the CBI's investigation into the massive PNB scam in which bank officials helped Nirav Modi and others get credit from overseas banks using fake guarantees. Nirav Modi and his family left the country in the first week of January.
Despite his financial troubles, Mr Kothari hardly cut back on his opulent lifestyle. His sprawling 'Santushti' mansion and a fleet of luxury vehicles are well known in Kanpur.
Vikram Kothari's father Mansukhbhai Kothari set up the 'Pan Parag' brand that became a huge success.
In 1999, the Kotharis split. Vikram Kothari took charge of the family's stationery and pens enterprise while his younger brother Deepak Kothari took control of the Pan Parag empire.