Michelle Rodriguez make quite an appearance at Marc Jacobs' fashion show, wearing a glamorous pearl dress and a alcohol monitoring ankle bracelet.

She is forced to wear the Secure Continuous Remote Alcohol Monitor because of drink drive offences. The £800 device is worn 24 hours a day by drink-driving offenders.

The device has a small pump inside which periodically scoops up a trace amount of perspiration vapour from the ankle, testing for alcohol. It records the level of alcohol every half-hour and once a day the offender must register the device with modem that transfers the data to the court.