The controversial cult which claims to have cloned five babies says it has discovered a way of reversing the ageing process.
The Raelian sect believes it can use stem cells to turn back the clock on any part of the body.
It says it has already carried out experiments which involve shortening ageing human DNA, which stretches over time.
The sect's claims are sure to reignite the controversy surrounding human cloning and the use of stem cells, which are obtained from foetuses.
Experts have admitted the techniques used are "good science" and that reversing ageing is "theoretically possible". However, they criticise the Raelians for refusing to reveal their methods and proof of their claims.
Cult chief Dr Brigitte Boisselier, 47, is set to reveal the details of the work at a conference in London next week. However, organisers, who say the cult used a false name to book their facilities, have now cancelled it.
"As far as I am concerned, this is just not science until they prove it," said Professor Christopher Higgins, director of the Medical Research Council's Clinical Sciences Centre at Hammersmith Hospital.
In an exclusive interview with the Evening Standard, Dr Boisselier said the cult had set up a new company, Stemaid, which is using stem cells. At least two patients are being treated; one has a brain tumour and the other is paralysed after a spinal cord injury.
"We have found a way to cure so many diseases and a way to look like you are 17 years old," she said. "There will be six to nine months demonstrating and then we will be showing everything."
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