The 28-year-old was also sentenced to community service totalling 20 hours by Judge Mitchell Scoggins at the Bartow County court, situated in the singer's home state of Georgia.

The sentence, handed down on Tuesday, stems from an incident on 4 July last year when the singer was stopped by police after being caught driving at 103mph (165km/h) on the Interstate 75 highway, a 70mph (112km/h) zone.

The 'Yeah!' star, whose full name is Usher Raymond, was driving a 2005 year model Range Rover.

After appearing before the judge, the five-time Grammy winner spent half an hour inside the courthouse to sign autographs for waiting fans.

Although Scoggins said the singer could complete the community service near Fulton, Georgia, his home town, the nature and completion date of the service were unclear.

Shortly after he had been pulled over, in August 2006, the 'Confessions' and 'Burn' star had taken on the role of Billy Flynn in 'Chicago'. But in October the singer was forced to withdraw from the Broadway musical following a throat infection.