A US-based fertility doctor claimed to have cloned 14 human embryos and transferred 11 of them into the wombs of four women in an interview published Wednesday.
Panayiotis Zavos told Britain's Independent newspaper that although none of the women had had a viable pregnancy as a result, the first cloned baby could now be born within a couple of years.
"There is absolutely no doubt about it... the cloned child is coming. There is absolutely no way that it will not happen," he said, quoted by the paper.
"If we intensify our efforts, we can have a cloned baby within a year or two, but I don't know whether we can intensify our efforts to that extent."
Zavos's work is widely condemned by mainstream fertility experts, who question whether the technique, which also raises complex ethical questions, is safe.
Although other scientists have created human cloned embryos in test tubes to extract stem cells for research, Zavos has broken a taboo by actually putting them inside women's wombs.
He said he has also produced cloned embryos of three dead people, including a 10-year-old girl called Cady who died in a car crash in the US. The child's blood cells were frozen and sent to Zavos.
The doctor, a naturalised US citizen born in Cyprus, is thought to have carried out the procedures in a secret laboratory somewhere in the Middle East to escape the US ban on cloning.
He uses the same technique as was used to clone Dolly the sheep, the first mammal to be cloned from an adult cell.
The procedures were recorded by a documentary maker and will be shown on the Discovery Channel in Britain later Wednesday.
In 2004, Zavos claimed to have implanted the first human cloned embryo into a woman's uterus although scientists then expressed scepticism over a lack of proof about his findings.
(c) 2009 AFP
Explore further: Rabbit eggs may be used for stem cells