The reach of Uncle Sam?s taxman in pursuit of unpaid revenue has apparently extended even to Singapore, despite the banking secrecy laws here in the U.S..

The Republic has reportedly become involved in an attempt by the United States tax authorities to identify tax evaders among an estimated one to two million American citizens who have opened offshore bank accounts.

The fact the taxman is going to this extent may seem astonishing to Singaporeans. But it makes sense when you realize that all income earned by US citizens is taxable, whether it is held locally or in other countries.

The information, which the US Internal Revenue Service (IRS) hopes will stem the loss of between US$20 billion and US$40 billion each year in tax revenues, is being sought from MasterCard International. This is because offshore bank account holders often use credit cards issued by MasterCard, Visa, American Express and other payment specialists to gain access to their funds from the US.

But whether the IRS will succeed in obtaining information such as the names and transaction records of such account holders is still an open question, because of the present US banking secrecy laws.

The expression "to stem the loss" means to