The first patents for cloning have been issued to the scientists who created Dolly the sheep. The patents cover the technology known as nuclear transfer and any animals that are produced using the methodology.

Dolly, the first mammal to be cloned from an adult cell, came into the world in 1996. Her creators at the Roslin Institute, just outside Edinburgh, Scotland, now want to use the technology to develop new ways of treating human diseases.

If they can find a way to clone healthy cells and reprogram them to become other types of cell - heart, bone, nerve, etc - it could be possible to make perfect-match tissue for use in transplants.

Scientists have high hopes for what is called therapeutic cloning and believe it could revolutionise medicine in the century ahead.

To achieve their goals, Roslin have entered into a private venture with the US-based Geron Corporation and have sought to protect their intellectual property.

New therapies

The UK patents, originally filed in 1995, have now finally come through; US patents should be issued in the coming months.

It will mean other commercial groups wanting to exploit the same technology would need to seek permission from Geron and be liable to pay a fee.

This has raised concerns once again about the use of patents to protect important medical technologies that have the potential to save millions of lives.

Sue Mayer, from the group GeneWatch UK, which is opposed to cloning, said the patents could actually hold back development of new therapies.

"In the past, this hasn't been the traditional way that medicine and treatments have advanced," she told the BBC. "For example, if we had patented innovations like in-vitro fertilisation, there would have been much less of it available through the national health system in the UK."

Restricted research

It is a view that has been echoed by Dr Vivienne Nathanson, head of science and ethics and the British Medical Association (BMA). She said society had to be worried about such developments.

"A tremendous amount of research is small scale and doesn't lead to an expensive drug which might bring money back in, and organisations, including charities, may not have the money to pay to use this patented technology," she said.

"So this could inhibit medical research."

But Simon Best, managing director of Geron Bio-med, the commercial tie-up between Geron and the Dolly scientists which now has the exclusive rights to use nuclear transfer, said applications to exploit the technology would be judged on their merits.

"If it is an area that we are developing, or an area in which we have reached an arrangement with large pharmaceutical company to invest a lot of money, only then would we seek to keep that for ourselves," he told the BBC.

Spur to innovation

Basic research would not affected, he said. Indeed, Mr Best said the patenting process had shown itself to be an enormous spur to innovation.

"Show me any evidence that the broad patents that covered transistors when they were invented in the 1950s in anyway held up the development of the computer or IT industries.

"Patenting has been proven time and time again to be the best way of bridging the gap between long-term research, risk and bringing new products to the market place."

But Dr Richard Nicholson, editor of the Bulletin of Medical Ethics, said those products would inevitably be more expensive as a result.

"Giving patents for discoveries that are not really new inventions but are just the result of many people's research inevitably makes healthcare more expensive, available to fewer people around the world, and just puts money into the pockets of shareholders."