The campaign featured press and TV advertising. The press ad stated: "If you find a better tasting beer, we'll eat our berets. The French know a thing or two about taste. That's why Kronenbourg 1664 is always brewed with the aromatic Strisselspalt hop for A Taste Supreme."
Small print in the bottom corner of the page stated "Brewed in the UK".
The TV ad, featuring footballer Eric Cantona, stated: "Here in Alsace, things are a little bit different. The hop farmers are treated like the footballers of Britain. They are idolised and adored. And why not? They are living legends. They are the men that grow the noble hops that make Kronenbourg the taste supreme ...".
On-screen text present in the corner of the screen for several seconds stated "Brewed in the UK".
One complaint to the Advertising Standards Authority (ASA) objected that the adverts gave the impression Kronenbourg 1664 is brewed in France, when it is actually brewed in the UK.
Another said the ads' claim that the hops for the lager was grown in France was misleading.
In its defence, Heineken UK stated that, despite being brewed under licence by their company in the UK, Kronenbourg 1664 was an inherently French beer. It had first been brewed in 1952 in Alsace by Brasseries Kronenbourg to celebrate their founder, it claimed.
It said in the UK it was brewed to a French recipe in a process supervised and approved by Brasseries Kronenbourg.
It added that a key ingredient of Kronenbourg 1664 was Strisselspalt hop, which was only grown commercially in Alsace, France, substantiating its claims with suppliers' letters.
On top of that, it pointed to the text in the adverts highlighting that brewing took place in the UK.
However, the ASA stated: "Although we acknowledged Heineken's arguments as to the beer's heritage and the French origins of the recipe, we considered that the degree of emphasis in the ad on the connection with France would lead consumers to believe that the entire brewing and manufacturing process took place in that country.
Contradicted rather than clarified
"The ad contained small print stating that the beer was brewed in the UK, but we considered that contradicted rather than clarified the main message of the ad."
It also stressed that, while Strisselspalt hops was grown in France, it did not constitute a significant majority of the total hops used in the lager's recipe.
It consequently upheld both complaints, ruling that the adverts should not appear again in their current form.
"We told Heineken UK to take care not to emphasise a connection with France to the extent that their ads implied that Kronenbourg 1664 was brewed in France, or that all or most of the hops used in the recipe were grown in France," said the ASA in its ruling.