The Central Bureau of Investigation on Wednesday said it has arrested 10 people in connection with the Punjab National Bank scam, PTI reported.

The arrested include two directors of Mumbai-based private firm Chandri Paper and Allied Products and eight officials formerly associated with the bank, The Hindu Businessline reported. They are accused of misusing the provision of Letters of Undertaking. These are letters of credit that banks use to tell one another that they will meet a customer’s liability.

In March, the Reserve Bank of India suspended the issuance of the documents, almost a month after the scam – India’s biggest bank fraud – was discovered. Authorities found that letters of undertaking were issued fraudulently by employees at Punjab National Bank.

The investigating agency said the accused were arrested for misusing letters of undertaking worth more than Rs 9 crore that were issued by the bank’s Brady House branch in Mumbai. It identified the accused as Ishwardas Agarwal and Aditya Rasiwasia, the directors of the private firm, and former bank officials Sanjay Kumar Prasad, Amar Sukhdev Jadhav, Sagar Dattaram Sawant, Bechu Bansi Tiwari, Yashwant Trimbak Joshi, Prafful Prakash Sawant, Mohinder Kumar Sharma and Manoj Hanumant Kharat.

On March 9, the CBI had registered a case against the two directors and some of the bank officials. A CBI spokesperson said the accused have been sent to police custody till December 21.

Businessman Mehul Choksi and his nephew Nirav Modi are accused of defrauding the Punjab National Bank of over Rs 13,000 crore and are being investigated by the Central Bureau of Investigation and Enforcement Directorate. Choksi was granted citizenship in Antigua and Barbuda in November 2017, and is believed to have been residing there since.