Some bars in Corfu, a popular tourist destination in Greece, saved patrons' unfinished drinks and then re-sold them to tourists as shots, Greek authorities said.

Officials discovered the practice during an operation to identify businesses that evade taxes or sell illegal drinks, according to CNN Greece and the Athens News Agency.

Auditors, led by the Independent Public Revenue Authorities with help from local police, raided several bars and restaurants between August 30 and September 1. Specifically, authorities investigated bars around the village of Kavos.

Although authorities were trying to determine if establishments were issuing receipts and serving smuggled or tampered alcohol, they discovered something else instead: repurposed drinks. Local news outlets reported that some establishments collected what was left from patrons' unfinished glasses, poured it into a barrel, and later served it to tourists as shots.

The operation also found tens of thousands of unissued receipts and several catering establishments that were serving alcohol that may been smuggled or even tampered with.

The businesses were forced to close for 48 hours and were issued fines, the outlets reported.

Representatives for Independent Public Revenue Authorities did not immediately respond to a request for comment.

The incident in Confu comes as Europe faces an influx of tourism this summer, according to The New York Times. The spike in visitors coincided with a number of stories about tourists behaving badly, including people drunkenly falling asleep in the Eiffel Tower and defacing the Colosseum.

In Greece, officials decided to limit the number of tourists who can visit The Athens Acropolis to 20,000 a day in an attempt to curb overcrowding.