The story begins in 2006 when an Agatha Christie fan bought a travelling trunk for £100 during a house clearing sale of the Devon home of Dame Agatha.

The trunk belonged to Dame Agatha's mother, Ciara. Inside the trunk was a locked strongbox, but the key had long been lost. Years passed before the new owner managed to open it, only to discover inside a purse of gold coins, a diamond brooch and a three stone diamond ring, belonging to Dame Agatha's mother.

The jewels found by the fan, were mentioned in Agatha Christie biography as pieces earmarked for the novelist and her sister Madge to inherit from their mother's collection.

Dame Agatha wrote: 'My mother's valuable jewellery consisted of "my diamond buckle", "my diamond crescent" and "my diamond engagement ring" ... Madge was to have the diamond crescent, I was to have the diamond buckle...'
' mother sorted amongst an array of odds and ends... all these required hours of sorting before they were packed in the trays in the various trunks.'

The fan is now selling the 19th century diamond brooch and three stone ring, at Bonham's auction house in October. The jewels are expected to sell for £10,000.00