Last year's terrorist attacks in the United States have led to a marked increase in suspected cases of money laundering in Switzerland.
The Swiss authorities said they had been notified of 417 cases of suspected money laundering last year, an increase of 34 per cent on the previous year.
In total the reported cases last year involved just over SFr2.7 billion ($1.7 billion). This is four times more than in the year 2000.
Releasing the latest figures in Bern on Friday, the Money Laundering Reporting Office said 380 of the 417 cases had been handed over to the judicial authorities for further investigation.
However, in the past only a few dozen cases a year ended in convictions.
The Reporting Office said nearly 100 cases of suspected money laundering were linked to inquiries into possible terrorist funding networks in the wake of the September 11 attacks in the US.
In many cases suspicions proved to be wrong, the authorities said. But some money still remains blocked in Switzerland as part of investigations into possible links to terrorist groups.
Of the total amount of SFr2.7 billion reported, more than SFr2 billion is related to international cases. They include the scandal surrounding the French oil company, Elf Acquitaine, over the controversial sale of navy frigates by France to Taiwan.
Judith Voney who heads the Swiss Anti-Money Laundering Office told swissinfo the increase in reported cases showed that Swiss laws are efficient.
"It shows that the financial sector in Switzerland has become more sensitive towards money laundering and suspected financing of terrorist activities."
Voney said she was pleased to see that the biggest increase in alleged money laundering was reported by the non-banking sector, and concerned fiduciaries and asset management.
However, there were only very few cases reported by lawyers' practices and insurance companies.
Most reports came from the regions of Geneva, Zurich and Bern.
Swiss laws to combat money laundering have been tightened in several stages over the past 25 years in a bid to combat organised crime.
The banks in 1977 first introduced an obligation to identify customers, and due diligence rules came into force in 1990. Under the rules banks have to report suspicious financial transactions.
Four years ago anti-money laundering efforts were also extended to the non-banking sector.
Voney told swissinfo that she was convinced that Swiss laws designed to combat money laundering and organised crime are strong enough and that Switzerland can no longer be considered a safe haven for dirty money.
However, a major case came to light in 1999 involving the late Nigerian dictator, Sani Abacha, and his business associates. They allegedly siphoned off funds worth hundreds of millions of dollars from the Nigerian central bank and deposited them abroad, notably in Switzerland and Britain.
Under an agreement signed between the Nigerian authorities and some of the defendants in the Abacha case Switzerland is handing back most of the money blocked in Swiss bank accounts.
swissinfo with agencies