Building work could be held up as critics call for investigation.

Construction of the London Olympic venues has hit its first hurdle after Tory London Assembly member Bob Blackman claimed that the site may be at risk of nuclear contamination. A week after London won the 2012 Games, the media backlash began as London's free-sheet The Metro warned that building work could be delayed by investigations.

Blackman accused the London 2012 team of being “blasé” about the risk from the reactor, which was built for undergraduate students from the now-defunct Department of Nuclear Engineering at Queen Mary College, and decommissioned in 1982. But Olympic press officer Mike Lee denied that there was a problem, and said that environmental advisors had assured the London Development Agency that there was “no nuclear contamination issue”. “We were not aware of this issue when we submitted the candidate file to the IOC,” he added.

In a statement, Queen Mary College said that the reactor was exceptionally small; the core was the size of a bucket and produced virtually no energy.”