The top-of-the-range vehicles were taken from Bell's showroom in Crossgar after the thieves broke into a secure office to steal sets of keys.

The cars stolen included a BMW and a Renault Megane.

It's believed they were stolen to order, fitted with new numberplates and later sold over the border.

Garage owner Charlie Bell said: "The cars are still out there somewhere but I don't think we will ever see them again. These people knew what they were after.

"We have stepped up our security at the showroom and I would urge other dealers to do the same. The stolen car industry is big business on both sides of the border.

"They knew what they were after and that's why they went for the keys. They seemed to be well organised but they won't stop us from working in the village."

A number of cars have also been stolen from homes in the plush Meadows area of Downpatrick, the nearby village of Saul and from Ardglass. Although some of the cars have been discovered in west Belfast, senior police sources believe this is a ploy by the thieves to make people think so-called joyriders were responsible.