The ANPR data is used by police to track vehicles
Civil liberties groups have voiced concern over plans to increase the length of time police store information on millions of UK car journeys.
Up until now data collected by the Automatic Number Plate Recognition (ANPR) has been kept for two years.
Information obtained by the Guardian newspaper indicates the data will now be kept for five years.
Privacy International said the database offered the police "extraordinary powers of surveillance".
About 10m journeys per day are currently being recorded using ANPR, but this is set to rise to 50m.
The Guardian has also obtained an ANPR strategy document for the Association of Chief Police Officers (Acpo), which advised officers to "fully and strategically exploit" the data gathered.
Police can access the database to locate uninsured cars, illegal licence plates and track criminals.
Simon Davies, director of human rights group Privacy International, said the powers afforded to the police by the database were "unnecessary and disproportionate".
He added: "This is possibly one of the most valuable reserves of data imaginable."
Privacy International said it has complained to the Information Commissioner's Office (ICO) over the plans.
The ICO said that "prolonged retention would need to be clearly justified based on continuing value not on the mere chance it may come in useful".
Merseyside Police's Assistant Chief Constable, Simon Byrne, who leads Acpo's ANPR policy, said: "Experience has shown there are very strong links between illegal use of motor vehicles on the road and other types of serious crime."