Human cloning could happen within the next half century, claims a Nobel Prize-winning scientist.

Sir John Gurdon, the British developmental biologist whose research cloning frogs in the 1950s and 60s led to the later creation of Dolly the sheep in 1996, believes that human cloning could happen within the next 50 years.

He said that parents who lose their children to tragic accidents might be able to clone replacements in the next few decades.

Gurdon, who won this year's Nobel Prize for Physiology or Medicine, said that while any attempts to clone a human would likely raise complex ethical issues, he believes that in the near future people would overcome their concerns if cloning became medically useful.

The 79-year-old scientist explained that people were extremely suspicious of in-vitro fertilization when it was first developed, but after the Louise Brown, the first 'test tube baby', in 1978, the technique gained wide acceptance and is used today by thousands of infertile couples worldwide.

He noted that cloning methods would first need to be refined before they can be applied to humans because the vast majority of clones today are deformed.

Gurdon said in an interview with BBC Radio Four's The Life Scientific that he had predicted at the time when he first cloned frogs that the successful cloning of a mammal would happen within 50 years and that "may be the same answer is appropriate" for the progression to human cloning.

"When my first frog experiments were done an eminent American reporter came down and said 'How long will it be before these things can be done in mammals or humans?'" Gurdon said in the interview.

"I said: 'Well, it could be anywhere between 10 years and 100 years - how about 50 years?' It turned out that wasn't far off the mark as far as Dolly was concerned. Maybe the same answer is appropriate," he said.

He explained that cloning a human being is essentially making an identical twin, and that doctors would simply be "copying what nature has already produced."

"I take the view that anything you can do to relieve suffering or improve human health will usually be widely accepted by the public - that is to say if cloning actually turned out to be solving some problems and was useful to people, I think it would be accepted," he added.

He said that in his previous public lectures, he often asks the audience whether they would be in favor of allowing parents of deceased children, who are no longer fertile, to create another child using the mother's eggs and skin cells from the first child if human cloning was made safe and effective.

"The average vote on that is 60 percent in favor," he said.

"The reasons for 'no' are usually that the new child would feel they were some sort of a replacement for something and not valid in their own right," he said.

"But if the mother and father, if relevant, want to follow that route, why should you or I stop them?" he asked.