In yet another sign of how the US and other G20 nations are relentlessly pursuing alleged tax evaders, US federal authorities are considering serving a legal summons toHSBC to see if it helped citizens evade tax, according to the New York Times and other media, citing unnamed sources.

The legal action was being considered as a federal indictment was announced yesterday that a client of an “unidentified international bank” on charges of conspiracy to defraud the US by keeping hidden bank accounts in India and the British Virgin Islands, an offshore tax haven, from about 2001 until this year, the NYT said.

The bank was HSBC, the paper’s sources said. The US Justice Department has not identified the conspirators, according to another report by Bloomberg.

HSBC, which last year reported that its private banking business in Geneva had suffered the theft of thousands of client accounts, declined to comment to this publication. In the past, the UK/Hong Kong-listed bank has not commented on such allegations.

The latest reports highlight how authorities in a number of countries have targeted banks – not just Swiss ones – as part of an attempt to crack down on alleged tax evasion via offshore financial centers. To date, the biggest case has involved UBS, which in 2009 reached a settlement with the US to pay a $780 million fine to settle criminal charges of aiding tax evasion, and also agreed to hand over some client names as part of a separate, civil case. A number of banks such as Julius Baer – also the victim of a client data theft – and Wegelin, no longer provide offshore banking to US clients.

In further details on the case which allegedly involves HSBC, reports said that the indictment, of Vaibhav Dahake, by federal prosecutors in United States District Court in Newark, said the unnamed bank had identified wealthy Indian-Americans as clients for undeclared offshore banking through NRI Services, a US division of the bank. The division, court papers said, encouraged US citizens to open undeclared bank accounts in India.

Dahake, of Somerset, New Jersey, was born in India and became a naturalized US citizen in 2006. He is a principal of Tricolor, an information technology business in Somerset.