Swiss authorities say it could take months, but they are pressing ahead with an investigation to find Swiss bank accounts linked to the former president of Argentina, Carlos Menem. Argentinian officials contend that the accounts contain millions of dollars Mr. Menem received from Iran to cover up its involvement in the bombing of a Jewish center in Argentina.

Former President Menem denies that he holds Swiss bank accounts or had contacts with those responsible for the bombing of a Buenos Aires Jewish center; 86 people died in the bombing, which took place in 1994.

Falco Galli is spokesman for the Swiss federal justice office in Berne. He says that Switzerland is investigating the charges lodged against Mr. Menem by a judge in Argentina.

"One of these hypotheses says that Iranian officials had paid $10 million to Carlos Menem and transferred the money on a bank account in Geneva," he said. "Menem, on his side, had declared that there is no evidence for responsibility of Iran for this attack."

Mr. Galli says Switzerland will not take action against Mr. Menem if it finds anything. All the information will be given to Argentina.

"If we find such accounts, then we hand over the bank documents so the judge can use this as evidence for his investigation," he said.

Swiss bank privacy rules generally do not permit the disclosure of bank names. But that confidentiality is lifted in criminal cases and therefore poses no barrier in this case.

Mr. Galli says Switzerland, at Argentina's request, is looking into other cases involving Mr. Menem. Argentinian justice officials allege that, from 1991 to 1995, the former president headed a $60 million arms trafficking ring to Croatia and Ecuador. They believe some of the money from the trafficking may be in Switzerland.