Justin Timberlake is set to propose to girlfriend Jessica Biel, according to reports.

The SexyBack star, 27, is rumoured to be on the verge of asking actress Biel, 26, to marry him, after dating for over a year.

A source tells British newspaper The Sun, "Justin is 27 and thinking about marriage and kids. For the first time in his life he is feeling settled and has definitely decided to pop the question to Jessica.

"He is so happy with her. They spent quite a bit of time apart recently when Justin was working with Madonna. That made him certain Jessica was the person he wanted to spend the rest of his life with."

And Timberlake is rumoured to be considering the West Indian island of Mustique for the pair's nuptials, as the land's private ownership means paparazzi would be unable to take photos of the couple and their guests.

The source adds, "Although Justin has lived his whole life in the public eye, he feels his wedding is the one day that should remain private. To get all his close friends and family to Mustique will cost a fortune. But he can't put a price on how he feels about Jessica."