Britain's cops have the largest DNA database in the world, and it's full of innocent people who were arrested but not charged, or charged but not convicted (the EU's Court of Human Rights have ordered this practice to stop, but the cops refuse to comply with the law — their latest dodge is to keep innocents' DNA for six years). Now an inquiry that begins today claims that police are "routinely arresting people" that they know they can't convict of any crime, simply to get their DNA into the database.

The highly critical report from the government's advisory body on the development of human genetics is published as the number of innocent people on the database is disclosed to be far higher than previously thought â€' nearing 1 million.

The commission says the policy of routinely adding the DNA profiles of all those arrested has led to a highly disproportionate impact on different ethnic groups and the stigmatisation of young black men, with the danger of their being seen as "an 'alien wedge' of criminality"…

The chairman of the commission, Prof Jonathan Montgomery, said: "It's now become pretty routine to take DNA samples on arrest. So large numbers of people on the DNA database will be there not because they have been convicted, but because they've been arrested."

He said the commission had received evidence from a former police superintendent that it was now the norm to arrest offenders for everything possible. "It is apparently understood by serving police officers that one of the reasons, if not the reason, for the change in practice is so that the DNA of the offender can be obtained," said Montgomery, adding that it would be a matter of very great concern if this was now a widespread practice.