According to Der Spiegel the federal prosecutor suspects that a man named as Sahed E., arrested earlier this week, delivered "on several occasions chemical products, control mechanisms and spare parts" to "an Iranian company known to be a supplier to the state defence programme."
Sahed E., who is based in the state of North Rhine-Westphalia in the north-west of Germany, sought to hide his activities by sending his deliveries through a shell company in Switzerland, Der Spiegel says, giving no source.
On Tuesday the federal prosecutor's office said it was investigating a man living in the Duesseldorf region in North Rhine-Westphalia.
He was said to have delivered since December 2005, via a shell company in a European country, "goods, technical control mechanisms and spare parts" to a country outside Europe."
The office said in its statement that it could not give details as to the man's identity or the country of destination to ensure the confidentiality of the inquiry.
Cases of export to Iran of material that could be used for military or even nuclear purposes are common in Germany.
In May two Germans were given jail terms for the illegal export of technologies that could be used by the Iranian armed forces.
In March German customs said they had uncovered an illegal network sending material to Iran for its nuclear programme via Russia.

Copyright AFP (Agence France-Presse), 2006