A “sneaky” Ian Thorpe said that he decided to return to the pool back in September and asked friends to lie in order not to expose his sensational swimming comeback.

Thorpe, 28, confirmed in Sydney on Wednesday that he would return to competitive swimming in a bid to contest the London Olympics.

Australia’s greatest Olympian said he would compete in the 100m and 200m freestyle focusing on the relay events.

Thorpe retired in 2006 after collecting nine Olympic medals from two Games including a record five gold.

He revealed on Wednesday that he had begun training five months ago – but went to extraordinary lengths to conceal it in case his bold comeback bid fizzled.

He trained at eight different pools in Sydney, asked friends to lie about his comeback, was coached via text by Australian swimming head mentor Leigh Nugent and did not tell his family that he was back in the pool until early January.

“I was really sneaky about how I did my training,” he said.

“I never confirmed or denied (a comeback) but I asked everyone else to lie through their teeth.

“I didn’t enjoy that level of deceit but I also thought it wasn’t people’s business.

“I thought I would get busted for it (comeback) a whole lot earlier … and that I would have to fly out an entire team to somewhere else in the world to get on with the training.”

He sparked rumours of a comeback when he was spotted in recent months training in Sydney.

Nugent also recently confirmed he’d been in regular contact, giving advice on how to regain fitness in the pool.

Thorpe confirmed he had registered for drug-testing to be eligible to contest the London Olympic trials in March 2012.