Former pop star and actress Sophie Monk has become engaged to her boyfriend Benji Madden after the US rock star proposed with a platinum ring.

Madden, of top rock band Good Charlotte, proposed on Christmas Eve, presenting Monk with a platinum and diamond engagement ring that Madden himself helped to design.

The stunning piece demonstrates the increasing interest in platinum as the perfect choice for celebrities preparing to tie the knot, helping to increase the metal's popularity with the public the world over.

Monk was said to be shocked at the proposal, but also "very excited", according to her spokesman, who was speaking to Australia's Daily Telegraph.

The pair have been together since the middle of last year and it is now to be seen whether the pair will choose platinum for their bridal jewellery.

Ÿ Adfero Ltd