Olympic and world champion Ian Thorpe said on Tuesday he would defend his 400 metres freestyle title at the Athens Olympics after the withdrawal from the event of team mate Craig Stevens.

Thorpe's hopes of swimming the 400 appeared to have sunk when he was disqualified for a false start after slipping off the blocks during last month's Australian trials.

He lost an appeal against the disqualification but was thrown an unexpected lifeline when Stevens, who finished second to Grant Hackett at the trials, gave up his spot on Monday, saying he wanted to concentrate on his other events, the 1500 freestyle and 4x200 freestyle relay.

"I'm pleased that I have the opportunity to swim this event at the Olympics and I'm grateful to Craig to have given me this opportunity," Thorpe told a packed news conference on Tuesday.