The Hinwil-based outfit, then under the guise of BMW-Sauber, took its only F1 triumph in Montreal in 2008 when Kubica headed home teammate Nick Heidfeld.

As a way of remembering its success, the team's factory has a display case that features all the champagne bottles from the 27 podiums it has scored in F1.

But Kubica's 2008 bottle is unique because it is the only one in its collection with the cork still in it.

The team says that a legend has built up – and one that new staff members are told on their first day at work – that the bottle is unopened because in his excitement of winning, Kubica forgot to uncork his champagne.

But, as Alfa Romeo explained in a team preview ahead of this weekend's Canadian GP, the real story behind the bottle is more complicated than that.

"It's a great Sauber story, one that shows the human side of Formula 1. It's a story new starters are told on their first days in the factory," said the team. "It's also not true."

The reality is that the winning champagne bottle became the centre of a row between BMW and Sauber over who should take ownership of it, with Kubica having actually sprayed it as normal before dropping it to team members.

"Sauber and BMW both wanted to keep the memento, the vessel of the sweetest champagne we had ever tasted," the team continued.

"We pleaded and begged but alas, on the occasion, it was the German giant that won 'The Battle of the Bottle': the original is proudly displayed in their Munich museum to this day."

With BMW taking ownership of the bottle, Sauber asked F1 to produce a replica bottle that Sauber could display at its factory – which is the one that is shown to this day.

"On the day, we chose to relinquish this precious memory to our partners," the team added. "That's what we did, with magnanimity and style. To go on building more great memories in the future.

"The trophy, that one we kept. From then on, we called it: "The one we didn't even give them a sniff of."

Kubica's victory in Montreal was the only win that the BMW-Sauber partnership would take, before the German car manufacturer and Swiss team split at the end of 2009.