A broken watch picked up for £10 at a car boot sale has sold at auction for £46,000.
The Rolex was discovered in a drawer by the late bargain-hunter's son, who was expecting it to sell for £500.
But the watched turned out to be a rare Rolex 17 Rubis Panerai 3636 watch - one of only 618 ever made - which were supplied during the Second World War to the Italian Navy.
They were issued to 'human torpedoes' - divers riding underwater missiles with a detachable warhead that could be used as a timed limpet mine on enemy ships.
The watches have a luminous dial to allow the divers to read them at night.
"It came to us on a valuation day by a chap with it in his pocket. The wind-up mechanism didn't work properly and so wasn't in perfect condition," Niall Williams, who sold the watch at auctioneers Wright Marshall in Cheshire, tells the Daily Mail.
"But we had a lot of interest in it and 10 phone lines taken up by bidders. When I told the vendor afterwards it sold for £46,000 he thought I had said £4,000 to £6,000 and I had to repeat it three times before he believed me."
Rolex is one of the most recognisable watch brands in the world, and its vintage watches tend to make much better investments than average. They aren't always as expensive as you might think, with some models changing hands for as little as £3,000.
The vale depends on the particular model, with rarer watches generally being worth more. The serial number will reveal the year of manufacture, the material and the movement, all of which affect the price.
The materials of the bracelet, dial, and bezel also influence the value: as you'd expect, platinum versions are worth more than gold, and some models are studded with diamonds.
The condition, too, is obviously important, and the original box and papers will bump up the price.
The most expensive Rolex ever to be sold was a stainless steel Daytona 6263 Albino - one of only four known examples, which formerly belonged to Eric Clapton. It went for £909,000 last year.