Berlin explosives experts have defused a British World War II bomb discovered under the city's Olympic Stadium.

The rusting bomb, which had a defective trigger, was detected under seats on Monday by construction workers restoring the stadium for the 2006 World Cup.

A 300-metre radius around the stadium was evacuated for the defusing, and the device taken away and destroyed.

Police said the bomb would have had a devastating effect if it had gone off while the 76,000-seat stadium, Germany's largest arena, was crowded.

"If you can imagine that peak crowds of nearly 100,000 people have been in the stadium at times, it would have been a disaster with many people killed and many with serious injuries if the bomb had gone off," said police spokesman Friedrich Christian Wehmann.

Nazi past

The stadium was built by Nazi architect Albert Speer for the 1936 Olympics and is now home to the football team Hertha Berlin.

The bomb was found just 50 metres from the place where Adolf Hitler used to be seen watching the Games.

Wartime bombs are still found regularly in Germany more than 50 years after the end of the conflict.

A report published in 1997 said there were still thousands of bombs and ammunition in and around Berlin and that the problem was expected to remain for another 15-20 years.