DNA techniques are constantly developing

Police have also gathered five and a half million sets of fingerprints, he said in his annual Police Foundation speech in London.

His comments came as new Home Office figures suggest it is increasingly obvious DNA evidence can be a potent weapon against all categories of crime.

The last three years have seen a 50% increase in the crimes solved using DNA samples.

Mr Blunkett warned the police to be prepared for "the next step-change in criminal behaviour and terrorist activity".

But he insisted the government was trying to stay one step ahead of the criminal.

Increasing Use of DNA 2002-03: 49,913 matches 21,098 detections 1998-1999: 21,329 matches 6,151 detections

He said: "The DNA and fingerprint databases have become vital weapons in law enforcement, making our communities safer by helping to put thousands of repeat criminals behind bars.

"Every week our national DNA database matches over 1,000 DNA profiles taken from crime scenes with names on the database.

"Around 42% of those matches are turned into detections within an average of 14 days."

He praised this as a "huge achievement", with nearly two million DNA profiles and five and a half million sets of fingerprints recorded.

If we exploit the new opportunities, we can put technological advances to good use in the fight against crime and terrorism David Blunkett Home Secretary

The government's Criminal Justice Bill plans to give police powers to take samples from anybody who has been arrested.

Currently it is only those charged with an offence.

Mr Blunkett warned that technology was equipping organised criminals with the means to carry out serious crimes such as drug running, people trafficking, fraud and terrorism.

But he claimed the government was striving to be "ahead of the game" and trying to predict the new phase in high-tech crime.

The use of the technique to fight crime commands overwhelming public support, but is opposed by civil liberties campaigners.

Gareth Crossman, of civil rights group Liberty, questioned whether a national DNA database was being made "by stealth".

The government is hell-bent on creating a national DNA database by stealth Gareth Crossman Liberty

And he added: "We are led to believe that DNA evidence is foolproof, yet Professor Sir Alec Jeffreys, the inventor of the DNA database, has warned that it is unsafe to use it to secure a conviction."

Some forensic experts evidence refer to the probability of match rather than a definite match.

They fear a potentially vast database may increase the chance of somebody being wrongly linked to a crime.

The government originally said in 2000 that it wanted to have three million personal profiles on the system by 2004.