The Genevan justice department has launched an enquiry into an incident of computer hacking at the World Economic Forum (WEF) summit in Davos last month.
Hackers broke into files stored on the WEF computer, and downloaded confidential information concerning 1,400 forum members.
As part of its investigations, the court has asked the Swiss German newspaper, "SonntagsZeitung", to hand over as evidence a copy of the CD rom containing information downloaded by the hackers.
The CD was handed over to the Sunday paper anonymously, but correspondents believe it was provided by members of "Virtual Monkeywrench", the group of hackers thought to be behind the incident.
The CD contains confidential electronic data about WEF members including their credit card details. Among those on the CD are Bill Gates, the head of Microsoft, and the Palestinian leader, Yasser Arafat.
Marc Tappolet, the judge overseeing the case, said he respected the fact that the newspaper wanted to protect its source, and is not asking them to declare who it came from.
The newspaper has so far declined to hand over the evidence.
swissinfo with agencies