ATHLETICS: Olympic champion hurdler Sally Pearson has torn a hamstring in training and reportedly won't compete at the Rio Games.

Pearson, the defending Olympic 100m hurdles champion, suffered the injury while training on the Gold Coast Australian news outlets reported on Wednesday.

A press conference will be held on Thursday with neither her manager or Athletics Australia commenting on the reports before then. 

The 29-year-old was to have been the Australian track and field captain at the Rio Games which start on August 5. She was due to race her heat on August 16.

Pearson, who missed the Australian summer domestic season, returned to her Gold Coast base after struggling in comeback races in Europe earlier this month when competing after a year-long absence because of a broken wrist and Achilles injury.

Pearson returned to Australia in a bid to find form and fitness after three sub-standard races in Europe.

The races were Pearson's comeback from a broken wrist and a torn calf muscle sustained in fall in a race in June last year.

"I was a little disappointed with my results and also disappointed that my body was letting me down a little," Pearson wrote on her website on June 18.

"This has been a big year, broken bones, torn calf, degenerative Achilles and hammy problems ... sometimes I wonder why I still continue to do this sport.

"What brings athletes back even after we get pushed down time and time again from disappointment? For me, it's the excitement, the fun and the pure determination that I can overcome the setbacks and still deliver my best."

Pearson won gold in her pet 100m hurdles event at the 2012 London Olympics in Olympic record time of 12.35 seconds, four years after winning silver in the event at the Beijing Games. Her season best time in Europe in 2016 had been 12.92.

The Queenslander won the world title in 2011 in 12.28 seconds, the fourth fastest in history. She was the 2013 world silver medallist and a dual Commonwealth Games gold medallist in the event. 

AAP and AOC