Indian authorities are probing a bank fraud case for potential money laundering

India’s Enforcement Directorate, a government agency that fights financial crime, will probe the possibility of money laundering in a $1.77 billion fraud case at the state-run Punjab National Bank (PNB), a finance ministry official said on Thursday.

PNB, the country’s second-largest state-run lender with assets of $120 billion, said in a regulatory filing that the fraud benefited “a few select account holders,” and that it has reported the matter to law enforcement agencies.

This was an isolated case of banking fraud and would be investigated by federal agencies, the finance official told Reuters. He declined to be named as he was not authorized to speak to media.

Separately, India’s Axis Bank said on Thursday that it had dealt in transactions that had been guaranteed with letters of undertaking from Punjab National Bank, but has since sold those transactions.

Shares in PNB, which fell 10 percent on Wednesday, were down more than 5 percent in early trading on Thursday.