Civil liberties groups are warning that the details of every Briton could soon be on the national DNA database, raising fresh concerns of a 'surveillance society'. Controversial plans being studied by the government would see the DNA of people convicted of even the most minor, non-imprisonable offences, such as dropping litter, entered on the national database.

The proposals are part of a wide-ranging government review of the Police and Criminal Evidence Act (Pace), which campaign groups warn may have profound ramifications for society. 'The danger is that if we start adding the details of people convicted of these sort of minor offences to the database we'll come to a tipping point,' said Gareth Crossman, director of Liberty. 'The government will say: "Actually it's a bit unfair some people aren't on the database; maybe everyone should be on it."'

The DNA database is already proving controversial with some politicians and police officers raising concerns about its use. Liberty claims that, per head of population, the UK has five times as many people on the DNA database as any other country. The government estimates that even if the database is not expanded to include the details of minor offenders, some 4.5 million people will still be on it by 2010.

The expansion of the database is prompting fears that people from ethnic minorities are being stigmatised. According to research by the Liberal Democrats, under the existing system within three years the details of more than half of all black men will be on the DNA database. 'The arbitrary method of collecting DNA will alienate minority groups who already feel unjustly targeted,' said Menzies Campbell, the Liberal Democrats' leader.

A three-month public consultation exercise on the government's plans to overhaul Pace concludes this month. The government intends to publish responses to the exercise in July and proposals will be put to ministers in January.

Currently, the police do not have the power to place details such as DNA and fingerprints of anyone who has committed a minor, or 'non-recordable', offence such as dropping litter or speeding on to the relevant database.

However, the government believes there may be a case for recording the details of people who have committed minor crimes. In a briefing document promoting the consultation exercise, the Home Office claims its inability to take personal details such as fingerprints or DNA from all offenders 'may be considered to undermine the value and purpose' of having a searchable database.

A Home Office spokesman said all options were being considered. 'The Pace consultation is about maximising police efficiency and ensuring that appropriate and effective safeguards are in place,' he said. 'We have made no decisions but we must consider anything which might free up police time or improve the efficiency and effectiveness of police investigations.'

Arguments that the DNA database should be expanded are growing. Writing in the latest edition of the House magazine, Lord Mackenzie of Framwellgate, a former president of the Police Superintendents' Association, said the case for including more people on the database was overwhelming. 'If I had my way, the DNA we now take from newborn babies to check for genetic disorders would be added to the national database in the national interest,' Mackenzie writes.

The DNA database has led to the successful prosecutions of rapists and murderers in recent years, sometimes decades after the crimes were committed. However, Simon Davies, director of the pressure group Privacy International, which campaigns against state surveillance, said such examples were a red herring. 'The problem is for every such instance if you expand the DNA database there are going to be multiple miscarriages of justice. This is the last domain. There's nothing left after this,' he claimed.

Privately, the Home Office anticipates a public backlash against the proposals. 'This is a completely open exercise,' one Home Office source said. 'If there is overwhelming opposition against this we will not go there.'