Plans for how long the DNA profiles of innocent people will be kept on the national database for England and Wales are being unveiled.
The Home Office will signal a retreat on adults arrested but cleared, who will all have their DNA profiles removed from the database after six years.
Only months ago the Home Office proposed holding the records of violent and sexual offenders for up to 12 years.
Under the proposals, 17 and 18 year-olds who are arrested for sexual and violent offences will still have their genetic fingerprints retained for six years even if they are released without charge or later cleared at trial.
Ministers say holding profiles of those without criminal convictions is needed to track down offenders.
They point to cases such as the murder of Sally Anne Bowman, which was solved because her killer Mark Dixie was on the database after an earlier arrest.
But details of the measures, reported in the London Evening Standard on Tuesday, have provoked outrage from civil liberties groups.
Shami Chakrabarti, director of Liberty, said: "It seems the Government still refuses to separate the innocent and the guilty and maintains a blanket approach to DNA retention.
"This grudgingly modified policy creates a repeat collision course with the courts and ministers look stubborn rather than effective or fair. Nobody disputes the value of DNA and anyone arrested can have a sample taken and compared to crime scenes. But stockpiling the intimate profiles of millions of innocent people is an unnecessary recipe for error and abuse.
The changes were prompted by a ruling in the European Court of Human Rights last year that holding indefinitely profiles from everyone who is arrested was "blanket and indiscriminate".
