The head of Switzerland's central bank says the bank will continue intervening in the foreign exchange market to stop the Swiss franc from gaining against the euro.
In an interview with Sunday newspaper NZZ am Sonntag, Philipp Hildebrand said: "We will not allow deflation to arise in Switzerland because of problems in the eurozone that are bringing about an excessive appreciation of the franc."
The newspaper estimated in an earlier report that the Swiss National Bank had bought up to 40 billion euros since January in a bid to stop the appreciation of the franc, which could hurt Swiss exports.
Another Sunday newspaper SonntagsZeitung, quoted analysts as saying that between Monday and Thursday, the central bank had purchased up to 30 billion euros.
Nevertheless, the Swiss currency hit a record high of 1.4044 francs against the euro on Thursday, as the European single currency slumped on Greek debt woes.
"Stability problems in the eurozone have a negative impact on Switzerland and it is therefore worrying for us all," said Hildebrand.
The chairman of the Swiss National Bank's governing board added that the central bank has to prevent both inflation and deflation from arising in Switzerland.