More yobs who get into alcohol-fuelled trouble in London could now be fitted with ‘sobriety tags’ to detect if they’ve been drinking.

A year-long pilot in the south London boroughs of Croydon, Lambeth, Southwark and Sutton has proved a success, so the scheme has been extended for six months and could be rolled out across the capital before possibly going national.

In the first scheme of its kind in the UK, offenders are fitted with round-the-clock ankle tags that monitor alcohol in their sweat.

Anyone found in breach of their sobriety order, either by drinking alcohol or tampering with their tag, is given a formal warning. A second breach leads to a fine or a tougher order, or in some cases a prison sentence.

So far 111 ‘alcohol abstinence monitoring requirement’ orders have been issued and more than 100 have been complied with.

The success rate of 91 per cent, with offenders staying sober for up to 120 days thanks to wearing the tags, compares favourably with an average compliance rate of 61 per cent for similar community-based orders.

Mayor of London Boris Johnson said: “Alcohol-fuelled crimes put a massive strain on frontline services and cost businesses and taxpayers billions of pounds.

“From drink-driving, to assault, theft, and criminal damage, our sobriety tags have proved a fantastic success in helping offenders across south London to stay off the booze and avoid the circumstances under which they might reoffend.

“It’s now time to bring this exciting new crime-fighting technology to the rest of the capital, and help remove the scourge of alcohol-fuelled criminal behaviour from all of London’s streets.”

The Mayor’s Office for Policing and Crime is extending the scheme for six months and looking at a London-wide rollout.

The scheme has also won government support.

Justice minister Andrew Selous said: "The results have been very encouraging and tie into the wider work we are doing to prevent people becoming victims of those who fail to control their drinking.

"The trial in London of using a tag to monitor how much alcohol has been drunk is an example of using technology to solve this problem, and we are committed to making it available nationally."