The Department of Health (DoH) is to install a biometric-based computer controlled methadone dispensing system (CCMDS) in 100 prisons in England.

The DoH has agreed a framework contract with supplier NEC for the system, which local Primary Care Trusts will install.

The biometrics aspect will help ensure the acuuracy of prescriptions, said Dave Marteau, the DoH lead on substance misuse.

"Biometric-based systems provide a level of patient safety that is highly desirable in a busy treatment environment," he said. "Biometric recognition linked to a computerised prescription is an excellent patient safety support for our clinicians.”

Prisoners will be subject to a biometric fingerprint or iris scan, before the methadone is dispensed.

The system will help cope with the increasing number of patients needing treatment in larger prisons – sometimes up to ten new patients a day.

Participation is optional, and the DoH said the system does not infringe human rights because does not physically store ‘images’ of biometric data - only the coding which enables an individual to be identified.