Builders working on sites for the 2012 London Olympics will need to pass through two stages of biometric security before they can start work.
Plans to introduce facial recognition technology and palm recognition to control the flow of visitors to the sites was introduced at a security conference in Abu Dhabi by Metropolitan Police Assistant Comissioner Tarique Ghaffur.
The decision to use technolgy that recognises palms rather fingerprints was taken because many workman have their fingerprints worn away during their work. At the height of the building work the technology could be used to process 10,000 builders.
At the same conference Ghaffur also suggested that there would need to be as many as 500,000 CCTV cameras.