Firms may have to revise their use of closed-circuit television to monitor workers following the publication today of a new code of practice by the Information Commissioner's Office.
The ICO found seven out of 10 individuals oppose the use of CCTV cameras that record their conversations, and half did not know the Data Protection Act covers CCTV surveillance.
The ICO said the use of sound recording was "highly intrusive" and warned organisations that its use would be justified only in "highly exceptional circumstances".
The code of practice outlines the key issues that organisations and businesses must consider when routinely capturing images of individuals on their CCTV equipment.
The code also sets out what they need to do to ensure individuals can use their rights.
Jonathan Bamford, assistant commissioner at the ICO, said the code would help people feel that the increasing use of CCTV surveillance would not result in a "Surveillance State".
"CCTV can be extremely intrusive, monitoring ordinary individuals as they go about their day-to-day business. It is essential that organisations and businesses use CCTV responsibly to maintain public trust and confidence in the use of CCTV and to prevent its use becoming increasingly viewed as part of the surveillance society," he said.
The code also provides advice on the retention and use of CCTV images and outlines some of the circumstances when it would be appropriate to disclose images captured by CCTV, for example, to law enforcement bodies for the investigation of a crime.