LONDON - Britain has built the world's biggest DNA database without proper political debate and police routinely arrest people just to get their DNA profiles onto the system, the genetics watchdog said in a report on Tuesday.

The Human Genetics Commission, which advises the government on the social, legal and ethical aspects of genetics, called for a review of the database and said new laws must be passed to govern its use.

In a damning report, the commission said "function creep" had transformed the system from a DNA store for offenders into a database of suspects.

More than three-quarters of young black men aged between 18 and 35 are on the system, the report said.

Set up in 1995, the database contains the DNA profiles of five million citizens, eight percent of the population, making it the world's biggest in proportion to population size.

"Parliament has never formally debated the establishment of the National DNA Database and safeguards around it," commission chairman Professor Jonathan Montgomery said in a statement.

"It has developed through amendments to laws designed to regulate the taking of fingerprints and physical evidence before DNA profiling was developed.

"It is not clear how far holding DNA profiles on a central database improves police investigations."

The report quoted an unidentified retired senior police officer as saying that "it is now the norm to arrest offenders for everything" in order to obtain a DNA sample.

‘Vital crime-fighting tool’
A Home Office spokesman said the database was a "vital crime-fighting tool" that had linked more than 410,000 crime scenes with a DNA match and a possible lead to an offender between 1998 and March 2009.

"Research shows no clear link between the level of offence for which an individual is arrested and the seriousness of any subsequent offence with which they may be associated," the spokesman said. No one from the Association of Chief Police Officers could immediately be reached for comment.

Opposition politicians and human rights groups said the report provided further evidence that Britain is becoming a "surveillance society," where people's personal details are stored and their movements constantly monitored.

Conservative Home Office spokesman James Brokenshire said Gordon Brown's government had allowed the DNA database to grow "for the sake of it, regardless of guilt or innocence."

"Under Labor's surveillance state, everyone is treated as a potential suspect," he said.

The report recommended that parliament pass new laws that clearly outline the powers of the police and the DNA database.

An independent panel should be set up to review the evidence on who has given DNA samples and why. The type of offences which require suspects to give a sample must also be reviewed.

Police in England and Wales can take and store the DNA of anyone arrested for a recordable offence, a category that includes all but minor crimes.