Indian media reported this week, based on a “right to information” query, that the frauds involved 1,885 cases, but SBI declined to say how much they had cost customers.

SBI, India’s largest lender by assets, said the fraudulent activity had been mainly in high-value accounts and that all of these had been classed non-performing assets “much earlier”, with most of the portfolio already fully provisioned for.

India’s banks have come under increased scrutiny after smaller state-run Punjab National Bank reported a massive $2 billion fraud last year.

This raised questions around the auditing and regulatory oversight of the country’s banks.