Six-time Olympic gold medallist Usain Bolt pulled out of his country's Olympic trials on Friday with a hamstring injury that has raised doubts over his fitness ahead of next month's Games in Rio de Janeiro.

Usain Bolt's Olympic quest could be in doubt.

The sprinting superstar left his country's national championships with a hamstring injury shortly before he was going to run the 100-metre final.

And that was just one part of a bizarre night at National Stadium.

Bolt's long-time rival Yohan Blake won the 100 meter title and formally qualified for the Rio Olympics - but only after a false-start disqualification call against him was overturned after review.

But even after Blake regrouped and prevailed, all the buzz was about Bolt and his status going forward especially since the national meet serves as the Jamaican Olympic trials.

He's not out of the Rio Games, but his status hinges now on how he does at a meet in London in three weeks time. Bolt said he was diagnosed with a Grade 1 hamstring tear - the most mild sort - and that the discomfort began presenting itself in his quarter-final race on Thursday night.

"I have submitted a medical exemption to be excused from the 100m final and the remainder of the National Championships," Bolt said in a statement released through Jamaican officials.

He added, "I will seek treatment immediately and hope to show fitness at the London Anniversary Games on the 22nd of July to earn selection for the Olympic Games in Rio."