One of the robbers shot at a police van as they drove off

Detectives believe the equipment was used to make false plates for vehicles used in the robbery at a Barclays Bank in Horwich, Bolton, in November 2006.

Det Ch Insp David Law said he believed the kit was stolen and that tracing the owners would help their investigation.

A �50,000 reward is offered for information leading to the conviction.

"We seized the equipment last month during a raid in the Westleigh area and believe it's more than likely to have been used to make the false plates for the silver Ford Mondeo and the red Ford Focus that were used in these incidents", said Mr Law.

The kit consisted of blank plates and numbers and letters

The number plate kit includes a wooden shelving unit with letters and numbers and a box of blank number plates. Police believe it was stolen in Wigan, Merseyside or Cheshire.

The gang raided the bank armed with a machete and a shotgun.

They escaped with a large amount of money after assaulting three bank workers and shooting at a police van.

The men drove off in a red Ford Focus, before swapping to a silver Ford Mondeo. Police said both cars had false plates.

Two men, aged 25 and 26, from the Westleigh area, arrested on suspicion of conspiracy to commit armed robbery, remain on police bail pending further inquiries.