Liu had been nursing ankle before big race

Superstar hurdler Liu Xiang had been suffering pain from an ankle injury in the build-up to the London Olympics, it was revealed after China's biggest athletic hope crashed out of the men's 110 metres hurdles for the second consecutive Games.

Liu drove into the first hurdle with his left foot and crashed to the ground, looking around in bewilderment in a case of dej?vu after a similar disaster at the Beijing Games in 2008. He then hopped on his left foot to the final hurdle and kissed it, as if to say goodbye to the race - and maybe his career - before getting on a wheelchair to seek medical treatment.

Feng Sheyong, the leader of China's athletics team, said initial reports suggested Liu had snapped his right Achilles tendon. He said the injury was 'quite serious'.

Feng said the 29-year-old former Olympic champion had never recovered from the ankle injury he sustained before the 2008 Games, which forced him to withdraw before he reached the first hurdle, breaking more than a billion hearts.

'Many reports said Liu had fully recovered from the injury, but he has not,' Feng said. 'He always has a strong reaction in his right ankle after each race, but fortunately most competitions finish in one race and he has ample time for treatment.

'The London Games is a bit different, with three races leading to the final. In preparing for them, there has been reaction in his ankle, but we did not expect it to be that serious.'