Behind this week's arrests on paedophile-related charges was a face recognition system developed by a Canadian and a British firm with the National Crime Squad.

Canada's Imagis Technologies and Britain's Serco are working with the NCS on a national database based on Imagis ID-2000 facial-recognition technology to use as a tool for keeping track of convicted paedophiles and other criminals, Imagis announced at the Biometrics 2001 Conference in London on Thursday.

The NCS confirmed the relationship.

Serco is a management and consulting company that has been providing IT support to the government and the NCS for a number of years. Imagis Technologies is a developer of image-identification software with a focus on biometric facial recognition.

Financial terms of the deal were not disclosed.

Imagis' ID-2000 was picked for further development by the government for its ability to identify an individual within very large databases of images in seconds, its ability to search for common background scenes as well as faces, its use imagery from any source, including live video as well as digital and analogue photos and the security built into the program that allows for the secure transmission of data even from remote databases, Imagis said in a statement that was vetted and approved by the NCS.

The software should aid law-enforcement agencies, such as the NCS, in identifying victims as well as perpetrators and even background imagery for criminal investigation and case preparation.

Already being used by the NCS, the face recognition technology is playing a part in the ongoing investigation into an online paedophile group which on Wednesday led to the arrest of 130 people worldwide, 10 in the UK.

The software is also being looked into as a tool for the fight against international terrorism, an NCS spokesman said.

Imagis system is, in essence, similar to systems used to recognise people in the real world, for example using CCTV cameras.

Such systems are known to be in place in the UK at major ports of entry - — places such as Heathrow and Gatwick airports, Dover seaport and the UK side of the Channel Tunnel.

In October, a US Senate subcommittee began looking into the possible future use of cutting-edge devices such as face recognition monitors and retinal scanners as a way to combat terrorism following the attacks in New York and Washington, DC in September.

The Imagis ID-2000 face recognition technology is also currently being used by the Oakland Police Department, in California including the Oakland International Airport.