This medal commemorating the taking of Porto Bello by Admiral Vernon in 1739 was among the items stolen from a country house museum in south Derbyshire on May 20.

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The items, all small medals and coins - mostly of historical and sentimental rather than great monetary value - were stolen during open hours from a bijouterie case which had its lock forced.

The crime reference number is 233 21/05/2009 and the police contact is DC Watson at Matlock CID.

Tel: 0345 123 3333.

• DEALERS are also being warned to look out for a man who has been stealing from shops in London's West End for some time and who recently struck two antique dealers in Duke Street.

The man is of North African appearance and is thought to have targeted at least seven galleries in the area over the last ten years.

He entered Grace Tsumugi Fine Art on April 9 at around 5.30pm and began to look around suspiciously. Acting confidently, he was carrying auction catalogues and, by distracting the owner of the gallery by asking to be shown certain objects, he managed to take a silver box and netsuke.

The incident took place a week after the Brian Haughton Gallery suffered the theft of a small pottery figure by the same man. A member of staff, who described the thief's manner as 'brazen', had evicted him from the premises when he entered to look around a few months beforehand.

The police officer dealing with the case is DC Wilds and the crime reference number is CRIS6501772/09. Anyone with information should contact Charing Cross police on 0300 123 1212.

• MEANWHILE, another initiative has been launched to help jewellers protect their premises from thieves.

The City of London Police have begun a scheme entitled Jewellery Watch, whereby 38 members of the trade in the local area will start receiving fortnightly email bulletins with updates on crimes committed and advice for prevention.

The jewellery shop owners have also been given a crime reduction survey and offered counterfeit currency advice. They are also being given a police contact list to report jewellery theft.

PC John Shickell from Snow Hill Police Station in the City said: "Jewellery Watch will encourage jewellers to exchange information about jewellery thieves and raise awareness of crime prevention and distraction thefts."