The 36-year old from the town of Oberursel, near Frankfurt, was guilty of possession of illegal weapons and falsification of documents, the court ruled on Monday.

The police arrested Halil D. and his wife in April last year, following a tip from a supply store that the couple had bought chemicals that could be used for homemade bombs. The two provided fake personal details during the purchase, police said.

Hundreds of cyclists were set to race in the annual May race near Frankfurt

During the search of the defendant's home, the authorities also found a pipe bomb, an assault rifle, ammunition and a bazooka grenade. According to unconfirmed information, the couple was scoping out the route of a large bicycle race scheduled for May 1. The officials canceled the event due to safety fears.

Islamist ties

The dual Turkish-German national was already known to police for a range of offenses, including assault. He was reported to have close ties with Islamist extremists in Germany. Police also said they found videos of a violent and extremist nature while searching computers seized in the couple's Oberursel residence.

The defendant's wife was soon released, however, after claiming she did not know about the materials her husband kept in the basement. She said they had bought the chemicals to remove mould.

During the trial, the man claimed that he had made the pipe bomb as a teenager some 20 years ago, and forgotten about it.

The court said there was not enough evidence showing that the defendant had considered an attack. Instead, he was convicted of keeping the illegal weapons cache.

dj/tj (dpa, AFP, AP)