Bianca Jagger is heading to court after refusing to pay a reward to a man who found her missing platinum and diamond ring.

Sir Mick Jagger's ex-wife claimed the band was worth $256,000 (£160,000) after she lost it in Salzburg, Austria in August 2008. It was returned to her the following month (Sep08) after Reinhard Ringler handed it in to authorities.

Jagger initially refused to hand over the $12,800 (£8,000) reward Ringler was entitled to under Austrian law, which states the finder must be paid five per cent of the item's value, citing his "long delay" in giving the ring back.

She subsequently offered to settle the dispute by giving the money to charity, but has since backtracked, alleging she made a mistake valuing the jewellery, and has now offered Ringler $1,280 (£800).

Ringler has begun proceedings to make the former model pay up, accusing her of making a "blatant attempt" to cheat him out of his finder's fee.

Jagger has a jeweller's appraisal valuing the ring at $24,000 (£15,000) to present to a court in Salzburg next Tuesday (05Feb13).