The Team GB athlete was initially delighted at clocking 12.75sec – 0.4 faster than the time she ran in Loughborough last August - in winning a race which included the United States' Olympic champion Dawn Harper (pictured below, right with Danielle Carruthers, left), until she learned about the extraordinary error.

"I am so annoyed," said the world heptathlon silver medallist, who is one of Britain's leading medal hopes at the London 2012 Games.

"I still had a good competitive race, but I've just not got the result I wanted."

A spokesman for Nova International, the event organisers, said: "There has been a technical error and there were nine sets of hurdles out on the course instead of 10.

"We'll conduct a thorough investigation and find out what happened and why and by whom.

"It's a very unfortunate mistake, we're very unhappy about it."


A Nova statement added: "We employ leading UK Athletics officials to manage this vital element of the event on our behalf, and we will of course be investigating this unfortunate occurrence further with them.

"On behalf of all those staging the Great City Games today, we would like to apologise for this unacceptable incident, and in particular to the athletes.

"We are unable to provide any further comment at this time until a more thorough investigation has been concluded."

Dwain Chambers finished second in the 150m, his first race since learning he can compete at London 2012 .

Chambers (pictured below, left) started strongly but American 200m specialist Wallace Spearman (pictured below, right) powered past the Briton in the final third of the race to secure victory by four tenths of a second.


"They are all challenges and I need to keep my head focused on the races I've got coming up," Chambers said.

The sprinter, who recently found out that he was eligible to seek a place in Team GB at London 2012 after the British Olympic Association lost its attempt to maintain lifetime bans for drugs offenders, added: "I need to stay injury-free and make sure I make the team."

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