Berlin- An Iranian businessman arrested a week ago in Germany on suspicion of illegal exports to Iran was a valued agent of the German foreign intelligence service BND, the news magazine Der Spiegel reported Saturday.

Prosecutors had advised the BND before the arrest they had no choice but to detain the man, 61, who had the code name Sindbad, because of suspicions that he was supplying equipment needed to make Iran's Shabah missiles, Spiegel said.

In a story to hit the streets in its Monday issue, Spiegel said Sindbad's intelligence deliveries to Germany included photographs of tunnel-drilling machinery, details of secret warehouses and up-to-date reports on Iranian missile development work.

His intelligence had been so good that the BND was even concerned he might be a double agent hoodwinking the West on Iran's orders.

Prosecutors announced Wednesday they had detained the man, who has dual Canadian and Iranian nationality, on October 5 on suspicion of breaching a German ban on export of militarily useful goods.

Spiegel said Germany was not just concerned at losing a spy who had served it for a decade and had been paid 1 million euros (1.4 million dollars), but also at potential tension with Teheran.

In addition, the BND feared the Iranians would try to assassinate the man in revenge if he were freed from prison in Germany, the magazine said. (dpa)