The scheme, which becomes operational tomorrow and will be controlled by the private security firm Group Four, could replace electronic tagging in the UK if it proves successful.
In the US, voiceprints have proved a popular way of tracking offenders released back into the community, with 19 states now using the technology. In California, all sex offenders released on licence are tracked using voiceprint technology.
The system, being piloted in Kent, is produced by the Dallas-based company The Voicetrack Corporation and involves the offender speaking over the telephone to register their voiceprint in a central computer. The offender is then issued with a dedicated BT pager.
At optimum times, such as when children are coming out of schools, the pager is used to contact the offender. They receive a message including a freephone number that must be dialled within ten minutes. It is the brief telephone contact then made that enables the system controller to identify and locate the caller.
A voiceprint is similar to a fingerprint in terms of the accuracy of identification with proponents claiming a 98 per cent success rate.
The National Association of Probation Officers is concerned that the project is another attempt to privatise the penal system. Harry Fletcher, its assistant general secretary, said: "This scheme is a form of privatisation and the real way of ensuring public safety is to properly fund the probation service, not to seek to plug the gaps with new technology."
A spokesman for the Home Office said: "This scheme is one of a number of things piloted from time to time."Reuse content