Jude Law buys Sienna Miller diamond ring for Christmas

The 'Alfie' actor - who reunited with the 'Factory Girl' star in October 2009 following a three-year split - stunned his girlfriend by hiding the diamond and sapphire jewellery inside another of her gifts, a restored grand piano worth £10,000.

News of the lavish gift fuelled speculation Jude and Sienna will marry next year.

In August, it was reported that Jude and Sienna celebrated their love in a marriage blessing ceremony in Southeast Asia.

The couple apparently took part in a traditional 'Baci' ceremony during a holiday in Laos, Southeast Asia, where their relationship was blessed by a village shaman, who tied their wrists together with red-and-white bracelets.

Prince Nithakong Somanith - cultural and artistic adviser to the United Nations Educational, Scientific and Cultural Organisation - met with the couple during their holiday and told them all about the ceremony, which is not legally binding, before sending them into the hills to meet the shaman.