The rare whisky was purchased by a Chinese guest at the Hotel Waldhaus am See in St Moritz, Switzerland, who paid 9,999 Swiss francs (£8019) for a 2cl measure of the Macallan, which was supposedly distilled in 1878, at the hotel's Devil’s Place bar at the end of last month.
However, according to online reports, the whisky is now thought to be a fake and the hotel has launched an investigation in a bid to get to the truth of the matter.
A number of whisky experts - led by experienced collector Serge Valentin - raised concerns after the story was posted online by website 20minuten.
Valentin and several others noticed several inconsistencies with the bottle including it's 'new looking' label and the mention of the 'Macallan and Talisker Distilleries Ltd', a company that no-one else has any knowledge of, not even Edrington or Diageo who now own the respective distilleries.
Hotel Waldhaus am See manager Sandro Bernasconi, whose father owns the collection the bottle came from, told whisky website Scotchwhisky.com that he had already contacted the unnamed Chinese guest to "tell him that it could be a fake" and said the hotel would reimburse him if it is.
Bernasconi added in the interview: "It’s very important to us to find out if it’s a real bottle or if it’s a fake."
"We’re open to find out the truth. If we had known it before, we would never have sold it."
At time of writing the investigation was still ongoing, and the bottle was in process of being sent to a special laboratory for analysis.