Thousands of unsolved criminal cases could be reopened after the discovery by scientists of a new DNA testing technique.

The revolutionary technology, called DNAboost, could shed new light on tens of thousands of cold cases from up to 30 years ago, including a number of high profile murders.

Officials behind the system, launched yesterday by the Forensic Science Service (FSS), say it enables them to separate mixed or poor quality samples of DNA. It is a world first in analysing samples that have been extremely difficult to interpret.

The FSS, which carries out forensic testing for police forces throughout the country, is piloting DNAboost with the police forces of West Yorkshire, South Yorkshire, Northumbria and Humberside.

The system is particularly effective in cases where more than one person has touched a surface. Previously there was a low success rate in distinguishing one person from another, particularly where DNA traces were small or of poor quality.

Tests suggest it will increase crime detection rates by at least 15% and will lead to scientists identifying 40% more samples than at present. Paul Hackett, DNA manager at FSS headquarters in Birmingham, said: "This means a great many more cases have the potential to be solved and a great many more families could look forward to securing justice."

British-based FSS runs the world's first and largest national DNA database under contract to the Home Office. The company can complete analysis in one week that might take a year in other European countries. The pilot scheme will run for three months, after which it will be available to other police forces in the country.

DNAboost is the biggest advance since the introduction in 1999 of Low Copy Number, which can match a minute DNA sample and was used by the Australian authorities to ensure the conviction in December 2005 of Bradley John Murdoch for the murder of Peter Falconio.

The FSS used a single hair as evidence to convict Sarah Payne's killer, Roy Whiting, who was found guilty of murder and kidnapping in December 2001.