(Phys) - Summer is the ideal time for breaking out a bottle of rose, but fans of French wine might think twice after millions of bottles were found to contain less costly Spanish tipple instead.

France's consumer fraud agency confirmed Monday that 70,000 hectolitres—the equivalent of 10 million bottles—of Spanish rose were falsely labelled as French vintages by hundreds of producers in 2016 and 2017.

According to French daily Le Parisien, which first reported the findings, Spanish rose sold in bulk at the time for just 34 euro cents ($0.40) a litre compared with 75 to 90 cents for French rose.

"We were alerted to the 'Frenchification' of Spanish wine at the end of 2015," the consumer agency's Alexandre Chevallier told the paper.

"So we launched an inquiry at all levels, from producers to importers to restaurants and distributors," he said.

Twenty-two percent of the businesses subjected to controls in 2016 and 15 percent in 2017—a total of 743 establishments—were cited for trying to present the foreign wine as French, he explained.