China's Olympic and world champion high hurdler Liu Xiang is unlikely to light the cauldron at the opening ceremony of the Beijing Olympics because he does not have time, his father and his coach have said.

As China's best hope of winning an athletics gold medal in August, the 110 metres hurdles world record holder was one of the favourites to perform the prestigious task of running the final leg of the torch relay.

"He has such weighty responsibility on the track, he will not be the one to light the flame," his father Liu Xuegen said.

Liu's coach Sun Haiping agreed that the 24-year-old center was unlikely to find the time for the lengthy rehearsals, given how tight their training schedule was.

"The opening ceremony is too significant, so there are lots of rehearsals - at least six times as far as I know, and they last a long time," he said.

"Especially the last rehearsal, the lighter of the cauldron must stay there for the whole day of August 7."

However, Sun stressed that Liu would definitely play an important role in delivering the flame to the Bird's Nest National Stadium by running at least one leg of the torch relay.

Reuters