Sydney - Olympic swimming great Grant Hackett is back in full-time training and could compete in Australia's national championships in April as he pursues his comeback following a troubled spell in retirement.
Hackett, 34, quit professional swimming in 2008 after winning the 1,500m freestyle at both the 2000 and 2004 Olympics, and claiming four world titles in the event.
But his life later spiralled out of control, including allegations he smashed up his Melbourne apartment and a messy divorce from singer-songwriter wife Candice Alley.
Earlier this year the former 1 500m world record-holder underwent rehab in the United States after seeking help for an addiction to sleeping pills.
He is now back under his old coach Denis Cotterell and training six days a week, with News Limited newspapers on Sunday suggesting the nationals were his short-term aim.
"I probably haven't felt this good since 2003 and 2004," Hackett said.
"This year I've just really got my passion back for it. I do set myself little goals and little times and I'm trying to improve, that's just the sort of person I am.
"Where it's going to lead I really don't know. My only ambition at this stage is to do a club relay with the boys."
Despite being upbeat, Hackett is conscious that comebacks at his age are not easy, with fellow Australian Ian Thorpe failing on his return to make the London Olympic team.
"(Ian) didn't make comebacks look overly attractive, it was probably more of a deterrent," Hackett said.
"That is probably why I'm more reserved and more humble because of watching that.
"At the age of 34, which is extremely old for swimming particularly after six years off, it becomes a challenge for me in my own mind of 'how fast can you go at this age?'"