The finger ring, which dates back to the 12th century, was found by a man metal detecting on farmland near Thwing last year.

The piece of jewellery, which is made of silver and contains traces of niello, was found by Dave Rooney on February 18, 2007.

The ring, which is 21mm in diameter, has not yet been valued but similar items found during the past eight years and entered into the annual treasure report have been valued between £550 and £650.

The silver ring was deemed to qualify as treasure at a coroner’s court hearing in Hull on Tuesday by East Riding and Hull coroner Geoffrey M Saul.

After the hearing a spokesperson for the British Museum said that the East Riding Museum Service had expressed an interest in the ring and they may choose to buy the piece of medieval jewellery from Mr Rooney once it has been valued by an independent treasure valuation committee.

He said the result of the valuation could be expected in around one month.

The shape of the ring is slightly distorted and broken in one place. It is made with thin silver and retains some niello and features two square and two rectangular panels connected by a series of grooves with a square bezel decorated with a star and dots.

Mr Saul explained the ring is classed as treasure in terms of its age and because it contains at least 10 per cent precious metal.

He passed on his congratulations to Mr Rooney for his find.