Reclaim your DNA
The Protection of Freedoms Act requires about a million innocent people's records to be removed from the National DNA database in England and Wales. In future this will be done automatically, rather than requiring you to write to the police.
The Government has announced that all DNA samples will be destroyed by May 2013 and all records on the DNA database and fingerprint database will be made consistent with the Act by September 2013.
In the meantime the "exceptional cases" procedure still applies and if you have not been convicted or cautioned for any offence you can still write to the Chief Constable of the police force which arrested you and took your DNA, asking for your records to be removed from the DNA and fingerprint databases and your sample destroyed. Wikipedia has a list of Chief Constables and police forces. You can find the contact details of the right police force on any letter they have sent to you about your arrest, or on their website. You can find the website of the relevant police force by searching on the Police UK website. Remember, your DNA may have been taken at a police station that is in a different police area from where you live.
In London, the police have issued an Early Deletion Procedure for people who were unlawfully arrested or mistakenly identified. You can use this procedure to request deletion of your DNA record and other data (including fingerprints, Police National Computer record and photographs) if you were unlawfully arrested in London.
BBC Online: Innocent people face DNA database 'shambles' (31st December 2009)
The Guardian: Innocent suspects' profiles still reaching DNA database (28th October 2009)
The Telegraph: Tory MP Damian Green has DNA profile deleted from database (20th August 2009)
The Guardian: Mark Thomas: How I got my genes deleted (19th March 2009)
The Register: Three months on, you still can't get off the DNA Database (2nd March 2009)
The Register: Don't delay: Delete your DNA (17th December 2008)