'Sobriety ankle tags' to monitor offenders' sweat
Around 2,000 offenders who commit crimes fuelled by alcohol are to be fitted with ankle tags to monitor whether they have been drinking.
The "sobriety tags" monitor sweat levels of the wearer every 30 minutes to see whether they have drunk alcohol.
New legislation enabling courts to order people to wear the tags has come into force across England and Wales.
Official estimates suggest two in every five violent offences are committed by people who are drunk.
Under the scheme, courts will be able to hand out an "alcohol abstinence order", requiring the offender to abstain from alcohol for up to four months and wear the electronic tag.
The technology is designed to be able to distinguish between alcohol-based products like hand sanitiser and can detect when contact is blocked between the skin and the tag.
During pilot schemes those who wore the tags were alcohol free 97% of the time, the Ministry of Justice said.
It says it expects 2,300 tags to be fitted to offenders every year.
Crime, policing and justice minister Kit Malthouse said the new tagging system will not only punish offenders but "can help turn their lives around".
The measures will be rolled out this winter.