Thorpe, who won three gold medals at Sydney in 2000 and Athens four years later, retired from the sport at the age of 24 in November 2006 because he claimed he had lost his motivation.

But now he has started training regularly again.

"I never really stopped swimming," said Thorpe, who also won three Olympic silver medals and a bronze.

"I'm just doing more now and I'm really enjoying getting into shape."

Thorpe is said to be motivated by old teammate Geoff Huegill's comeback.

The 28-year-old has also recovered from a serious shoulder injury, a triple break in his scapular, which hindered his training efforts last year.

Thorpe's manager David Flaskas said Thorpe had not ruled out competing in London next year, but he stressed he was yet to formally look to return to competitive swimming.

He is yet to register for drug testing and until he does so will not be able to compete on the world stage.

After registering with the World Anti-Doping Authority (WADA), an athlete must wait nine months before they are allowed to race again.



"At the moment he's training hard and loving swimming again," Flaskas said.

"He's not put his name down to race again.

"It will be nine months before he can race after he puts his name down for drug testing.

"He's enjoying getting fit again.

"To come back to competitive racing would be going up another level again.

"He was really happy for Geoff.

"But Thorpie's very much his own man."

Huegill led the calls for Thorpe to comeback in time for the Olympics.

"I think it's awesome and unreal," Huegill said.

"I hope he does want to compete for Austalia in 2012.

"One of the best things having a guy like that back training and lurking in the background will actually lift the level of competition.

"It will make guys step up."