Canton Geneva's chief prosecutor, Bernard Bertossa, says it will be almost impossible to identify assets belonging to terrorists. His comments come as the United States steps up efforts to combat money laundering in the wake of the September 11 attacks.
In an interview with swissinfo, Bertossa said the authorities would be hard pressed to track funds belonging to the Saudi dissident,. Osama bin Laden, who the US suspects is the chief suspect behind the attacks on the World Trade Center and the Pentagon.
"It is almost impossible to follow the money trail," Bertossa said. "There is obviously an organisation that finances these criminals, but there aren't any accounts with bin Laden's name on them."
Bertossa said terrorists must be receiving financial support from some states, but there is little chance of discovering where these funds originate. He added that Washington should look at its own banking laws before putting pressure on other countries.
"In America, it's possible to open a bank account without knowing who the owner is. It's the same in France for an offshore company, which can open an account without revealing the name of the real owner. This is impossible in Switzerland."
Bertossa told swissinfo that the scale of corruption and the sums involved made it impossible for the authorities to identify and prosecute more than a fraction of financial crimes.
"The interests of corrupt people are too vast for all illegal financial transactions to be brought to the notice of judges."
Last week, the Swiss government pledged to join international efforts to search for money linked to terrorism. The finance minister, Kaspar Villiger, said there was "no indication that bin Laden and his organisation have any funds in this country".