An extra £33m is to be spent on increasing the number of closed-circuit television cameras in England and Wales.

About 180 sites have been selected by the Home Office for the security cameras, which ministers say play an important role in curbing crime but civil liberty campaigners say invade people's privacy.

Cameras have become widespread in shopping centres and town and city centres since the early 1990s.

Research in Newcastle upon Tyne, where one of the first CCTV systems was introduced in 1992, showed crime fell significantly in the city centre area covered by a network of cameras.

Local councils in other parts of the country who use CCTV have also claimed sizeable reductions in crime.

But human rights groups question the figures on crime reduction, suggesting that the cameras just force criminals to operate elsewhere.

They have also raised concerns about the lack of legal controls on what the cameras look at, and how the pictures are used.