Despite spending 200 million over ten years installing and maintaining 10,000 CCTV cameras across the capital, just one in five crimes get solved, according to figures obtained by the London Assembly's Liberal Democrats.
The party said the statistics show that more CCTV cameras don't necessarily lead to a better crime clear-up rate.
Liberal Democrat policing spokesperson Dee Doocey said: "Across London, a mere one in five crimes get solved and boroughs with thousands of CCTV cameras are no better at doing so than those which have a few dozen."
In 2006/07, Hackney had 1,484 cameras - the most in London - and solved 22.2 per cent of its 31,166 crimes. Brent has just 164 CCTV cameras, but solved 25.7 per cent of its 30,474 crimes. The rest of the statistics can be viewed here.
"CCTV cameras have cost the taxpayer in the region of 200m in the last 10 years. Some of this money might have been better spent on police officers," said Doocey.
"Although CCTV has its place, it is not the only solution in preventing or detecting crime and too often still, calls for CCTV cameras come as a knee jerk reaction," added Doocey. "It is time we engaged in an open debate about the role of CCTV cameras in London today."
At its annual conference last week, the national Liberal Democrat party called for the government to rollback surveillance techniques, including cancelling the identity card scheme, updated the Data Protection Act, reviewing the role of the Information Commissioner, destroying DNA samples from innocent people and increasing regulation of CCTV.
Liberal Democrat Shadow Home Secretary Nick Clegg MP said: "Britain has long distinguished itself by its liberal belief in the rights of the individual against the powers of the state. By stealth, this Government has given the state unprecedented snooping powers that affect each and every one of us. It is time that these powers were rolled back."
