On Thursday the German federal prosecutor's office arrested 53-year-old Helmut R., in Friedrichshafen in southwest Germany, on suspicion of involvement in the delivery of 24 long-distance detonators, a device indispensable to the development of nuclear arms.

While the prosecutor's office gave no indication of the destination of the detonators, according to Der Spiegel they were to be delivered to Iran, but authorities intervened in time to stop the operation.

Prosecutors said the German national had been released on bail but was being investigated for conducting secret activities and aiding nuclear development.

As part of the investigation, several companies were searched in Germany and Switzerland around the Lake Constance area on the border.

Swiss cantonal officials confirmed searching two companies on Friday.

In February, the International Atomic Energy Agency (IAEA) submitted a list of 15 persons suspected of participating in the development of Iranian and Libyan nuclear programs.

On the list were three Swiss citizens and a German living in the Swiss canton of Saint Gallen.

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