Australian swimming great Ian Thorpe is "quite sick" in a Sydney hospital after contracting two potentially deadly infections and will never swim again competitively, his agent says.
The 31-year-old five-time Olympic gold medallist contracted the bugs after undergoing a series of surgeries on his shoulder at a hospital near his home in the Swiss town of Ronco sopra Ascona.
He has returned to Sydney and is receiving treatment at an intensive care ward.
Thorpe has received a number of visitors in hospital and is said to be in good spirits, despite the apparent seriousness of his illness.
"It's serious but it's not life-threatening," Thorpe's agent James Erskine told AAP.
"He's contracted two forms of bugs in hospital. He's undergone two or three operations over the last two months so ... I mean bad luck. He's quite sick but that's the situation."
Mr Erskine rubbished reports Thorpe could lose the use of his arm because of the infections but said Thorpe would never swim again competitively.
"From a competitive point of view - he will not be swimming competitively again I don't think," Mr Erskine added.
"The shoulder operation was a major operation, he's got as many plates as Barry Sheene (the now deceased world champion motorcycle rider)."
It's understood the infection contracted by Thorpe is similar in nature to the potentially deadly Methicillin-resistant Staphylococcus aureus (MRSA) superbug that has swept some hospitals in Europe.
2GB radio personality Alan Jones, a good friend of Thorpe's, said: "There may well be restricted movement - minor in a sense in the left shoulder.''
And as far as swimming competitively again, "well, that was never on anyway, so his swimming days are over,'' he said.
"Ian's getting himself better.''
Former teammate Matt Welsh said Thorpe was unlucky to have caught a super bug.
"It's pretty unlucky, every surgery has its risks.
"He's pretty strong physically and very strong mentally - I'm sure he'll be able to bounce back.''
Welsh said the "toughest pill to swallow'' for Thorpe would be that it was unlikely he would swim competitively again.
"I'm not sure what his long-term plans were but you definitely want to keep your options open,'' Walsh told the Seven Network.
"Ian's been very unlucky with all his attempts to get back in the pool.''
It is the latest upset in Thorpe's life.
Australia's most decorated swimmer with 11 world championship golds, Thorpe was admitted to hospital earlier this year to treat depression after he was found disoriented in Sydney.
Police were called when a resident saw Thorpe behaving oddly near a vehicle and his manager Erskine later said he had been taking a mixture of anti-depressants and medication for his shoulder.
Thorpe won three golds in his Olympic debut at the 2000 Sydney Games and clinched another two at Athens four years later, but surprised by announcing his retirement in 2006 at the age of 24, citing a lack of motivation.
Thorpe announced he would return to the pool in 2011 in a bid to qualify for the London Games but he flopped at national trials the following year and failed to make the team in either of his targeted 100 and 200 metres freestyle events.
Describing the comeback as a fairytale "turned into a nightmare", Thorpe said he would continue swimming.
He later revealed in his 2012 autobiography "This is Me" of a near decade-long battle with depression, including suicidal thoughts and regular alcohol abuse.
Though frustrated by injury setbacks, Thorpe last year told local media he had not ruled out a bid for the 2016 Games in Rio.