Experts say the tests are a significant development in the fight against crime. They will be especially useful if the police are trying to establish whether a crime is racially-motivated.

Scientists would have better evidence to present in court

One senior forensic scientist said developments in DNA testing techniques would also allow scientists to provide much more solid evidence when comparing traces found at the scene of a crime to the DNA profile of a suspect.

"In general, this kind of information should be invaluable to police and help save time and resources - it's certainly a significant development in our work with DNA," said Dr Dave Werrett, director of research and DNA Services at the Forensic Science Service.

At the moment, scientists know that the chances of two people in the UK having the same DNA profile are about one in 50 million. That means they would not expect to find two people in the UK with the same profile.

But the results obtained from the new testing techniques mean that scientists can say with confidence that the chances of two people having the same DNA profile are even more remote - one in a million million.

"That would mean that the chances of the DNA fitting the profile of anyone else in the UK would be almost non-existent," added Dr Werrett.