For the vinuous Aladdin’s cave that it was, the surroundings were rather prosaic. The metal ramp and bare neon lights below ground at Fortnum and Mason, the famed London department store, were light-years away from the waist-coated staff and crystal chandeliers of the store’s wine section. Yet there was nothing prosaic about the names on the wine boxes stacked in a corner: Bordeaux legends from stellar vintages, fine old cognacs and vintage ports. And all of them apparently ownerless, or at least without owners that could be found.

I had been led into the bowels of the Piccadilly store by James Taylor, the man who had spent the past two years reducing the forgotten treasure to its present proportions. Fortnum’s, being at the finer end of the shopping experience, used to offer free cellaring to people who bought wines from it. But in 2000 commercial reality collided with genteel intent; the cellar had become crowded with these private reserves and extra space was needed by Fortnum’s expanding wine business. The owners would have to be found and the wines delivered.

Yet with no annual reminder to pay the cellar rent, contact between the store and the owners lapsed, sometimes for decades. Mr Taylor handed me a bulging red notebook inscribed ‘Customer Reserves 1981-’. The top of each page contained a name and address. Below it was listed the wines bought and cellared. Another column showed when bottles were withdrawn: sometimes en bloc, sometimes piecemeal as special occasions demanded. Across some pages ‘Cleared’, scrawled in thick ink, marked a successful end to the search.

Other pages bore the scars of a trail gone cold: Fortnum’s envelopes posted to last known addresses and returned unopened. Letters went to Hong Kong, Singapore and the US, to name a few. The executor of the estate of Mr Robin Angus wrote to confirm the latter’s passing away and acknowledged receipt of 10 bottles of Chablis Vaulorent 1966, which would be passed to his widow.

Fortnum’s caught up with Miss M.R. Barbeau before the Grim Reaper; her case of Le Montrachet Marquis de Laguiche 1976 has been ‘cleared’. The record-keeping recalls a pre-consumerist age of individual attention.

We speculated about the genesis of this generous service. “We have been in this building since 1929,” pondered Mr Taylor, who started at the store in 1988.

“ And it would have been around the time of World War II that fine wine started to be drunk by people who might not necessarily have a country house with a deep cellar?” I ventured.

“ Perhaps,” he agreed and pulled out some evidence in support: a bottle of Chateau Margaux 1943 bought - and forgotten - by a Mrs Winham. “This is our oldest bottle,” he said.

What would happen if the owner could not be found? “Initially we thought we would have to sell most of the private reserves, but we have been so successful at tracing the owners - only 50 of the more than 200 people have not yet been found - that the pressure on space has eased. We will still sell some, but with the Margaux we might ask the chateau if they have any of the 1943 in their cellars - it was a war vintage - and donate it to them if not. It might keep us in their good books!”

Some of the wines people have laid down had long passed their drinkability. “A lot of the stuff just went off - corks crumbled and it became a health risk. The solicitors we wrote to, sometimes offered to pay us to dispose of the wine, but we just washed it down the drain,” said Mr Taylor. Not, of course, without a little taste for the staff!

“ Some of the wines were surprising. You would not expect much of a 40-year-old Beaujolais, but the 1959 Moulin-a-Vent from Louis Latour had quite a lot of flavour left, although it dissipated quickly. Still, we did give a bottle as leaving present to someone who was born in 1959. She was thrilled”. Yet this was an exception - all the wines they tasted went down the plughole regardless.

But the outstanding ones remained. In 1982 C.R. Bennington remembered to collect the magnum of Dom Perignon 1961, the case of Chateau Latour 1962 (“one broken during re-binning”) and 12 bottles of Chateau Mouton-Rothschild 1962 - then still a second growth - that he had bought 20 years before. Maybe the intervening years had diminished his taste for cognac; he left the bottle of Hine Antique and Martel Extra, which Mr Taylor now stood admiring. “There is no leakage and the seal is intact. Once the spirit is in the bottle, it does not change.”

An invoice on five cases of 1992 Fonseca port evidenced purchase by “Mrs R.M. Illingworth for George Robinson, c/o Maj. R.A. Robinson”. “We got lots of christening presents,” explained Mr Taylor.

Another prize haul recently purchased and apparently forgotten was that of Mr Mazakazu Katsura. When he collected his 1985 clarets in 1990, he added some cases from two of the finest Bordeaux vintages since the war: Chateaux Cheval Blanc, Pichon-Longueville Comtesse de Lalande and Beychevelle 1982 and some Lynch-Bages and Cos d’Estournel 1989. Fortnum’s has pursued him unsuccessfully across continents.

With such a collection of apparently ownerless luxury items, the store has had some ‘opportunists’, especially after an article in London’s Independent on Sunday revealed the existence of the forgotten cellar. “We have had a few crank calls, things like ‘my old granddad may have had some wine.’”

If there have been wishful thinkers, there have been celebrities too. Mr Taylor’s path crossed with Ol’ Rubberlips himself. He showed me the page recording the wines purchased by the rocker in 1974 and 1978: 1906 Croziet cognac, tequila and a case of Chateau Beychevelle.

“ I am sure it was Bianca Jagger who laid it down, so when we wanted to deliver the wine, we were uncertain whether to contact Mick or the former Mrs Jagger. So we played it safe and went through the record company,” Mr Taylor confesses.

When an international firm of accountants celebrated 25 years in business in 1989, they were looking for some 1964 champagne to celebrate. Mr Taylor obliged with some forgotten bottles of Krug: “If any champagne will last that long, it is Krug. But we did have a taste to ensure it was still drinkable. It had retained its mousse and developed honeyed tones - quite special!”

Yet the most extraordinary leftover in the Fortnum’s cellar is neither champagne, nor spirit - it is a fine old Bordeaux first growth. Mr Taylor reverentially lifted the lid off a dozen bottles of Chateau Latour 1949. Each bottle was still shrouded in its original straw wrapping. Mr Taylor unveiled one bottle; the level was still above the shoulder. Robert Parker has rhapsodised about this wine: “The 1949 Latour [100 points] is one of those wines that can take a taster’s breath away.”

Parker not only determines the monetary fate of new Bordeaux vintages. Mr Taylor showed me the result of his accolade in a recent catalogue: “very high shoulder/very good label/vintage on capsule (RP100) - £1450”, it read.

Multiply that by 12, add a small margin, some VAT and a premium for the original packaging and you are looking at more than $A100,000 of wine bought and forgotten.

Someone, somewhere is not kicking himself. And he should be.