The United States has asked for detailed information on US nationals who have hidden their money in Switzerland, the paper said, basing its report on a three-page letter from the US deputy attorney general James Cole, dated August 31, addressed to the Swiss authorities.
The letter concerned Switzerland's second biggest bank, Credit Suisse, as well as around another 10 banks, notably Julius Baer, Wegelin, and the cantonal banks of Zurich and Basel, the Sunday paper said.
US authorities want all the data concerning private customers and US foundations which have deposited at least $50,000 (€35,000) in Switzerland between the period of 2002 and July 2010.
This latest request is not the first by US officials. Switzerland's biggest bank UBS was forced to disclose the names of 4,450 US clients for whom it had offered to conceal funds from the eyes of the US tax inspectors.
The bank paid a fine of $780 million to avoid losing its banking licence in the United States.
According to an anonymous banker quoted by SonntagsZeitung, Swiss banks risk a fine of around two billion francs ($2.5 billion) to settle this latest tax evasion affair.