The company says that such elevated prices – up to double the market value in some cases – are reserved for cars that are cheaper to run in countries where fuel costs are lower, in particular large, petrol-engine executive models. The company adds that some British leasing and vehicle remarketing companies are now cashing in on the phenomenon by cherry-picking suitable cars to specifically offer to exporters, despite the costs of shipping and the depreciation that occurs while holding the cars on docksides, often for several months.

Recent examples have included a six-year-old Citroen C8 sold for £5,600, which CAP "books" at £2,200 in the UK, as well as a five-year-old Audi A4 selling for £15,400, more than double its UK CAP trade value of £7,175, and a four-year-old Honda Civic diesel that went under the hammer at £20,600, almost £12,000 more than its usual value at home.

CAP adds that there is even growing demand from eastern European countries for older and damaged cars – especially 4x4s – which are often snapped up for spares and the chance of cheap motoring.

CAP believes that there are many reasons for the strength of overseas demand, depending on the type of vehicle leaving British shores. The 2011 Japanese tsunami devastated that country's new car production capacity for months, while writing off an estimated 230,000 used cars and thousands more new cars which were destined for export. The British market has since been helping to make up for that country's 80% reduction in exports, according to the company.

CAP reckons such trade is pushing prices ever higher in the UK and creating shortages of certain models. It adds that the used vehicle export phenomenon is not confined to cars, with its experts also reporting a constant flow of trucks, trailers, motorcycles and vans abroad as the export trade grows every day. In particular, Ford Transits and Mercedes Sprinters are being frequently snapped up by exporters.

CAP's Mike Hind said: ‘This is one of the biggest untold stories of recent years across the UK used vehicle markets. Our car, bike, truck and van experts are often astonished at the prices they see paid for vehicles destined for export and there is no sign that demand will dry up any time soon.

‘Sometimes it is causing real issues for dealers and traders in our own markets, with real pain being felt by bike dealers in particular, at present. But elsewhere it is helping to remove a considerable number of vehicles that would otherwise struggle to attract any interest here.’