The Central Bureau of Investigation (CBI), India’s top investigating agency, has raided the Mumbai office of Cyril Amarchand Mangaldas (CAM) in relation to the biggest fraud by an Indian bank, according to a report on the website Legally India (LI).

Earlier this month, India’s Punjab National Bank, the second-biggest state-run lender, stunned the country’s financial sector when it announced it had discovered an alleged fraud worth $1.8 billion at a single branch in Mumbai, according to Reuters.

LI said that CAM was instructed by Nirav Modi, billionaire jeweller and one of the main accused in the case, before the fraud was discovered. The law firm reportedly cooperated with the CBI and handed over all documents related to the Modi mandate. After the fraud came to light, the firm terminated the mandate.

According to the LI report, other firms that have been instructed by Modi in the past include Luthra & Luthra, which advised the Modi-promoted Firestar Diamond on its plans for an IPO, and DSK Legal, which is understood to have worked with Modi’s company in the past on standard corporate transactions.

Modi, who disappeared once the fraud was detected and is reportedly now in Sylvan St. Kitts, located in the eastern Caribbean, is being represented by advocate Vijay Agarwal, LI said.