The world of athletics is still in shock after Usain Bolt's false start saw him disqualified from the men's 100m final at the World Championships in Daegu.

But it now appears that Bolt's false start may have been caused by a twitch from his main rival.

Eagle-eyed fans have pointed out that the Jamaican superstar's blunder was sparked by an early move in his blocks by Yohan Blake.

As our video below shows, Blake clearly shifted in his blocks moments before the gun went (there is a close-up replay at the 12-second mark), with Bolt appearing to react to his main rival for the gold rather than wait for the gun.

IAAF rules state clearly that competitors must not move once in the starting blocks, suggesting that it was actually eventual winner Blake who should have been disqualified - as Britain's Dwain Chambers had been for a similar twitch ahead of his semi-final.

Judge for yourself whether Yohan Blake should have been penalised as his leg shakes (0:14 seconds into video)

Sprint legend Ato Boldon - a former World Championship gold medallist - agreed on his Twitter feed that Blake moved in his blocks, yet had little sympathy for world record holder Bolt.

"Yohan Blake flinched but no excuses for Bolt. Gotta focus on ur lane," wrote the Trinidadian sprinter, now an analyst for US television.

Following Bolt's exit many have called for the instant-disqualification rule to be changed before next year's Olympics, with the silver and bronze medallists in Daegu speaking out against it.

"That false start (rule) is killing us," second-placed Walter Dix said afterwards. "Hopefully it will change by London (2012 Olympics)."

Veteran Kim Collins of Saint Kitts and Nevis, who finished third, also wanted it overturned or at least modified.

"At least give the field one false start," Collins said.

But Bolt himself refused to either grumble or offer up excuses.

"Looking for tears? Not gonna happen," he said.

"Of course I am extremely disappointed not to have had the chance to defend my title due to the false start.

"I was feeling great through the rounds and was ready to run fast in the final. I worked very hard to get ready for this championships and things were looking good.

"However I have to move on now as there is no point to dwell on the past."

Eurosport