RARE malts worth hundreds of thousands of pounds could be cheap modern fakes, experts warn.

Analysts claim professional fraud in the rare whisky market could be “more commonplace than ever previously considered”.

The warning comes after a 113-year-old bottle set to fetch up to £100,000 at auction was discovered to be a modern fake containing spirits distilled less than 10 years ago.

Brokerage and investment firm Rare Whisky 101, which made the discovery, has also revealed two other fakes worth up to £250,000 and £500,000. The Dunfermline-based company says the revelations come at a time of “dynamic growth” in the market, when more opened vintage bottles are coming to light.

However, there are now doubts over the provenance of some of these lots and co-founder David Robertson says the revelation could undermine investor confidence and derail the lucrative trade.

About 55,000 bottles will have been sold in the UK whisky auction market alone by the end of the year, with the sector turning over around £12 million.

Robertson, a former master distiller with Macallan, said: “The risk for the market is that we’re seeing an increasing number of old, rare archive or antique bottles coming to market, and it’s very difficult for the untrained eye to verify authenticity.”

It took six months of laboratory tests to verify that one bottle, labelled as a 1903 Laphroaig, was nothing of the sort.

While scientists confirmed the glass bottle matched methods used in the early 1900s and an assessment of the make-up of the liquid matched the profile of a Laphroaig, containing peat-derived compounds to prove a connection with Islay, it was found to be a blended drink distilled around 2007-09.

The bottle, which had been in circulation for “a good few years”, had come from Spain and Rare Whisky 101 opened it for tests after buying it for a low four-figure sum on approach from an auction house unsure of its authenticity. The team has also confirmed two part sets of Macallan Fine and Rare are also counterfeit.

Oxford University was among the teams commissioned to work on the project, which was the first of its kind.

Robertson said: “Our Laphroaig 1903 would seem to suggest that there are now some very good quality fakes which have been recently created to fool unsuspecting connoisseurs, collectors and investors into parting with serious money. Indeed, the forgeries that we’ve uncovered could be just the tip of the iceberg.

“Our message to whisky fans is ‘buyers beware’. Don’t take the chance to acquire rare, old, antique-looking whisky unless you can be 100 per cent sure of its provenance.”

Co-founder Andy Simpson said the pair had initially been “hugely excited” by the Laphroaig, which is “like hens’ teeth” due to its rarity.

Describing the bottle, he said: “The glass looked good, the label looked good. It looked like one of the best examples of this type of whisky that we have seen so far.

“What it turned out to be is one of the best examples of how to fake a bottle of Scotch.”

He went on: “Despite a very convincing aesthetic, our bottle, which had been circulating at auctions for a good few years, was most certainly a fake and quite possibly the most expensive young blended scotch in the world. This result, whilst personally disappointing, goes to show that we’re really dealing with some top-class imitations.”