BRITISH police are studying Chinese-style surveillance tactics as they prepare security for the 2012 London Olympics, a leaked Scotland Yard report has revealed.

The report, marked “restricted”, reveals that among the “Big Brother” tactics deployed at last summer’s Beijing Games was the installation of miniature microphones in thousands of taxis.

The bugs transmitted passengers’ conversations to a police control room. There, officers could activate disabling devices to stop the cabs if they suspected criminal activity.

In another operation, athletes, visitors and journalists were believed to have been tracked by tiny microchips on their tickets and passes.

Software linked to the city’s 300,000 CCTV cameras was capable of recognising known criminals and terrorist suspects.

The 44-page police report says there are “lessons to be learnt” from China’s use of digital surveillance. But it warns: “The fine balance between the use of technology to support security requirements and individual rights to privacy will be an open debate in the UK for 2012.”

The study was prepared after a trip to the Beijing Olympics by Tarique Ghaffur, a former assistant commissioner.

Ghaffur chaired the police committee on Olympic security. He completed the study last October before he was forced to step down following a dispute with the then Metropolitan police commissioner, Sir Ian Blair.

It has been circulated to chief constables, MI5 and senior Whitehall officials as they draw up the £600m security plan for 2012.

Ghaffur last week declined to comment.

However, Alan Campbell, the Home Office minister, has revealed that the Home Office is investigating technology that would allow police to halt a vehicle remotely.