Swiss banking secrecy, which has historically played a key role in driving the country’s success as a financial centre, received a potential further blow at the weekend when its justice minister suggested tax evasion should be treated as a crime.

At present, tax evasion is a misdemeanour, not a crime – contrasting with the practice of countries such as the US, UK or Germany. Tax fraud - deliberately misleading the tax authorities - is a crime in Switzerland.

Swiss tax authorities should be treated in the same way as foreign ones, Justice Minister Eveline Widmer-Schlumpf said in an interview with the weekly NZZ am Sonntag, according to a translation by Reuters.

Bank secrecy has already been partly eroded in Switzerland. Last August, the Swiss and US governments reached an agreement under which UBS, Switzerland’s biggest bank, will hand over up to 4,450 client account details to US authorities, as part of a civil case concerning alleged tax evasion by UBS clients. In a separate, criminal case, UBS has handed over about 250 client details, and agreed to pay a $780 million fine to settle charges.

"The question arises whether in the long term we should abolish the distinction between tax fraud and serious cases of tax evasion domestically as well," Ms Widmer-Schlump was quoted as saying.

Banking laws make it a crime in Switzerland to provide details of an individual's bank account.

Ms Widmer-Schlumpf said the Swiss authorities would not help foreign tax authorities with investigations into tax cases that were based on stolen bank data. Germany said this month it would pay €2.5 million for stolen Swiss bank data with details of tax evaders.

Banking and financial services account for about 13 per cent of Swiss gross domestic product.