Massive investment in CCTV cameras to prevent crime in the UK has failed to have a significant impact, despite billions of pounds spent on the new technology, a senior police officer piloting a new database has warned. Only 3% of street robberies in London were solved using CCTV images, despite the fact that Britain has more security cameras than any other country in Europe.

The warning comes from the head of the Visual Images, Identifications and Detections Office (Viido) at New Scotland Yard as the force launches a series of initiatives to try to boost conviction rates using CCTV evidence. They include:

· A new database of images which is expected to use technology developed by the sports advertising industry to track and identify offenders.

· Putting images of suspects in muggings, rape and robbery cases out on the internet from next month.

· Building a national CCTV database, incorporating pictures of convicted offenders as well as unidentified suspects. The plans for this have been drawn up, but are on hold while the technology required to carry out automated searches is refined.

Use of CCTV images for court evidence has so far been very poor, according to Detective Chief Inspector Mick Neville, the officer in charge of the Metropolitan police unit. "CCTV was originally seen as a preventative measure," Neville told the Security Document World Conference in London. "Billions of pounds has been spent on kit, but no thought has gone into how the police are going to use the images and how they will be used in court. It's been an utter fiasco: only 3% of crimes were solved by CCTV. There's no fear of CCTV. Why don't people fear it? [They think] the cameras are not working."

More training was needed for officers, he said. Often they do not want to find CCTV images "because it's hard work". Sometimes the police did not bother inquiring beyond local councils to find out whether CCTV cameras monitored a particular street incident.

"CCTV operators need feedback. If you call them back, they feel valued and are more helpful. We want to develop a career path for CCTV [police] inquirers."

The Viido unit is beginning to establish a London-wide database of images of suspects that are cross-referenced by written descriptions. Interest in the technology has been enhanced by recent police work, in which officers back-tracked through video tapes to pick out terrorist suspects. In districts where the Viido scheme is working, CCTV is now helping police in 15-20% of street robberies.

"We are [beginning] to collate images from across London," Neville said. "This has got to be balanced against any Big Brother concerns, with safeguards. The images are from thefts, robberies and more serious crimes. Possibly the [database] could be national in future."

The unit is now investigating whether it can use software - developed to track advertising during televised football games - to follow distinctive brand logos on the clothing of unidentified suspects. "Sometimes you are looking for a picture, for example, of someone with a red top and a green dragon on it," he explained. "That technology could be used to track logos." By back-tracking, officers have often found earlier pictures, for example, of suspects with their hoods down, in which they can be identified.

"We are also going to start putting out [pictures] on the internet, on the Met police website, asking 'who is this guy?'. If criminals see that CCTV works they are less likely to commit crimes."

Cheshire deputy chief constable Graham Gerrard, who chairs the CCTV working group of the Association of Chief Police Officers, told the Guardian, that it made no sense to have a national DNA and fingerprint database, but to have to approach 43 separate forces for images of suspects and offenders. A scheme called the Facial Identification National Database (Find), which began collecting offenders' images from their prison pictures and elsewhere, has been put on hold.

He said that there were discussions with biometric companies "on a regular basis" about developing the technology to search digitised databases and match suspects' images with known offenders. "Sometimes when they put their [equipment] in operational practice, it's not as wonderful as they said it would be, " he said. "I suspect [Find] has been put on hold until the technology matures. Before you can digitise every offender's image you have to make sure the lighting is right and it's a good picture. It's a major project. We are still some way from a national database. There are still ethical and technical issues to consider."

Asked about the development of a CCTV database, the office of the UK's information commissioner, Richard Thomas, said: "CCTV can play an important role in helping to prevent and detect crime. However we would expect adequate safeguards to be put in place to ensure the images are only used for crime detection purposes, stored securely and that access to images is restricted to authorised individuals. We would have concerns if CCTV images of individuals going about their daily lives were retained as part of the initiative."

The charity Victim's Voice, which supports relatives of those who have been murdered, said it supported more effective use of CCTV systems. "Our view is that anything that helps get criminals off the street and prevents crime is good," said Ed Usher, one of the organisation's trustees. "If handled properly it can be a superb preventative tool."