Australian Olympic swimming champion Michael Klim speaks about rare disorder chronic inflammatory demyelinating polyneuropathy

Australian swimming great Michael Klim has revealed he has a rare auto-immune disorder that has left him with little or no feeling in his feet and means he cannot walk unassisted.

The Polish-born Klim represented Australia in swimming at three Olympic Games, winning two gold medals. He famously setting a new 100m freestyle world record in the lead-off leg of Australia's world record-breaking 4x100m freestyle relay win at the Sydney Games in 2000.

He also broke the 100m butterfly world record twice and won seven long-course and five short-course world titles in various events, plus five gold medals at the Commonwealth Games.

Klim told Channel 10's The Project that he had first realised he had an issue three years ago when he was forced to sit on the floor at Kuala Lumpur airport because his legs could not support him.

"I called [Klim's partner] Michelle [Owen] and I was literally in tears, because I couldn't pinpoint what it was," he said.

"That was one of the scariest moments I had. For me, my ability to do anything physical was something I used to pride myself on, and used to give me mental strength. And bit by bit [it] was being taken away.

Klim has since been diagnosed with a rare auto-immune condition, chronic inflammatory demyelinating polyneuropathy (CIDP).

"The body is trying to protect itself, but it's eating its own tissue," he said. "In my case it's eating the outside of my nerves."

The 44-year-old Klim said he has lost sensation in both his feet, with a little function remaining in his left foot. He has also lost use of both calf muscles and his left quad.

He uses braces or a walking stick to move around. Klim — who runs a swimming school in Bali — gets in the pool a few times a week to provide relief for his legs.

Klim lives in Bali with his partner Michelle Owen and his three children he shares custody of with his ex-wife Lindy Rama-Ellis.

However, treatment for his condition requires him to travel away to Sydney for weeks at a time to have immunoglobin replacement therapy.

His partner said the deterioration in Klim's condition had been difficult to cope with for his children.

"There was one significant moment where Michael kept falling over and was unable to hold himself up and it was happening in front of the kids too," Owen said.

"That was when they really thought there's something really going on with dad and it was quite scary for them to see that."

Klim has had a number of other health issues — at one point he required back surgery to relieve compressed nerves.

"I had two nurses to help me, I couldn't even get to the bathroom," he said.

Klim said a number of his old Olympic teammates have provided help and support.

"Chris (Fydler) for instance, walking out for an appearance, he would say 'I'll walk in front of you just a little bit so if you need to grab my belt or something'," he said.

"My friends actually astounded me."

Other old swimming friends also pitched in, including Daniel Kowalski and Ian Thorpe.

"He (Thorpe) gave me the nickname the 'human walking stick', because that's what I am for Michael," Owen said.

Klim said Owen's love and support had been crucial since his diagnosis. 

"She's been a rock for me because I could end up in a wheelchair one day," he said.

"It's funny the people I've told about my CIDP, they've said 'that's OK, you're an Olympic athlete, you've got that mental strength to get you through this.

"And it's actually not necessarily been the case. It's not like I can do extra exercise … if anything, at times I've been more despondent about it and it's more depressing.

"I give myself an hour a day to feel sorry and angry and frustrated and whatever emotion comes in my mind – and then I move on with the rest of life."