Timberlake is also suing UK newspaper The News of the World

A judge in Santa Monica, California, granted the order against photographer Artemus Earl Lister on Tuesday.

The singer's spokesman Ken Sunshine said it was "about time" something was done about photographers who often follow celebrities by car.

"Unless somebody has the guts to carry this through legally, somebody's going to get killed through these chases.

"It's about time that somebody did something about these stalkerazzis," he said.

Timberlake sought the restraining order against Mr Lister on 7 July.

Timberlake and Diaz's relationship has attracted media attention

Last week, it was revealed the singer was suing the News of the World newspaper for libel, saying a report bout his private life was untrue.

Media lawyers Schillings issued libel proceedings after a request for damages and a retraction of the story was refused.

Managing partner Simon Smith told BBC News Online the company would pursue the claim with "some vigour".

But a spokeswoman for the Sunday newspaper told BBC News Online it would stand by its story.

"We will vigorously defend these proceedings in court," she added.