“The government has not yet decided,” Leuthard told broadcaster Deutschlandfunk ahead of a meeting with German Chancellor Angela Merkel in Berlin.

Some Swiss parliamentarians are demanding legal action, and there are lawyers who say that Germany overstepped and broke international rules when it bought the confidential data.

“We still hope to find a solution with Germany as to how to proceed with this illegal data,” Leuthard said.

Despite the tensions over the bank CD – which has helped Germany rake in hundreds of millions of euros from tax dodgers – the two countries are “very good friends” and neighbours, the Swiss president said.

A new dual-country tax accord agreed upon by the two countries in late March could be a solution to the problem, she said. According to the agreement Switzerland would provide administrative cooperation according to OECD standards. But the country insisted it would not cooperate in cases of stolen bank data.