Hundreds of innocent teenagers have had their DNA details logged by Sussex Police, the Government has revealed.

The force has built a database containing the genetic details of 644 under-18s who have never been convicted, charged or cautioned for an offence.

Their DNA profiles will be kept alongside data on criminals until they die, providing a bank of information for officers investigating future crimes.

The youngsters' details have been stored by police after being arrested, despite being later released without charge.

The figures were released by Home Office minister Andy Burnham, who defended the action after requests from MPs.

Mr Burnham said: "Taking a DNA sample and fingerprints from someone who has been arrested for an offence and detained in a police station is now part of the normal process.

"It is no different to recording other forms of data such as photos and witness statements.

"Early research has shown that sampling persons who have been arrested but not proceeded against has yielded a match with a crime scene in more than 3,000 offences.

"These links may never have been made had the police not been given powers to take and retain samples on arrest.

"Retention of the DNA profile on the National DNA Database may prove vitally important in the event of a person committing a crime in the future."

The database holds details on more than three million people, including 124,347 who have been subsequently released without charge or caution. Of those, 24,168 were under 18.

Mr Burnham added that police could store DNA details on arrest, regardless of if they are later convicted.

He said: "The samples may only be used to prevent and detect crime, to investigate an offence, to conduct a prosecution or to identify a deceased person or body part.

"DNA samples are normally kept until the person is 100 years old or dead."

Sue Beatty, who has a 15-year-old daughter and a 12-year-old son, was horrified to learn of the genetic database.

Mrs Beatty, 50, of Walsingham Road, Hove, said: "It's outrageous. I fully support using biometric information when crimes are committed but if a teenager who has done nothing wrong has their DNA taken without their knowledge it is a serious breach of civil liberties."

Keith Taylor, Green party convenor at Brighton and Hove City Council, said: "This is just another example of the Big Brother culture that seems to obsess the Government."