Marking a week since the time of the incident, officers are carrying out 'anniversary checks' in Burnthurst Lane between 9am and 11am.

The Princethorpe man, who owns a jewellery store in Birmingham, was stopped as he drove out his home in a black Mercedes on July 11 around 10am.

A knife was held to his throat and three masked men bundled him into another vehicle, believed to be green, close to the junction with the B4453 Leamington Road.

Two accomplices drove the Mercedes, registration DA55 EUR, towards Coventry Road while the other car followed.

The 62-year-old victim was told his house would be burned and his family killed if he did not help.

The cars were driven past the Burnt Post public house on the A45 and split up at Sparkbrook, Birmingham. The Mercedes stopped at Punjam Zevar Jewellers, where the shop-owner was forced to reveal the codes, but the robbers panicked when they entered the shop.

Shortly afterwards, the victim was let out the car at Swanhurst Lane, Moseley. The robbers had taken a £1,800 gold chain from his neck, keys to the shop's safe, a mobile phone, credit cards and cheque book.

Anyone who may have information should call Rugby CID on 01788 541111 or Crimestoppers anonymously on 0800 555111.