(Photo: Gran Centenario)

Mexican health authorities have issued a public alert over an adulterated batch of tequila recently linked to five deaths in the state of Guanajuato.

Last Monday, the Federal Commission for the Protection against Sanitary Risks (COFEPRIS) warned that bottles of Gran Centenario Añejo labeled with the lot number L 06124 had been flagged for “product irregularities” by brand owner Casa Cuervo. The 950-milliliter bottles were sold through online platforms and appear to have been tampered with by an unknown third party.

Concerns were raised in early June, when a quinceañera party in Salamanca, Guanajuato, resulted in five deaths and nearly 40 hospitalizations. Sources interviewed by People Magazine reported that individuals experienced vomiting, headaches and blurred vision after they consumed the adulterated tequila. The tragic incident has now been linked to the same lot number warned of by COFEPRIS.

The government says the counterfeit bottles can be identified by a detached cap and a front label that lacks embossing.

“The counterfeit and adulterated product was sold through online sales platforms and does not comply with the specifications set forth in [regulation] ‘NOM-142-SSA/SCFI-2014. Alcoholic Beverages: Health Specifications, Health and Commercial Labeling.’ As a result, it poses a risk to public health, since the raw materials used are unknown, as are the conditions under which it was produced, bottled, stored and distributed,” COFEPRIS said.

Mexican newspaper Milenio claims to have obtained one of the offending bottles and has published an extensive list of additional warning signs, most of which have not been independently confirmed by health authorities. According to Milenio, the adulterated tequilas contained superimposed stickers, fake Tax Administration Service labels, hidden expiration dates and evidence of recycling. A QR code on the side — which would typically link to the message “If you’re going to drive, don’t drink” — reportedly opens a web page that never finishes loading.

Gran Centenario is one of the most popular tequila brands in Mexico, and is produced by the same parent company as Jose Cuervo, 1800, Gran Coramino and 400 Conejos.

It is not unheard of for recognizable spirits brands like Johnnie Walker or Casamigos to be counterfeited on the black market. However, filling a once-legitimate bottle with fake booze makes it all the more difficult to ascertain a spirit’s authenticity, especially when those bottles appear to have been sold through standard retailers.

Anyone who has information about the “possible commercialization” of lot 06124 is encouraged to file a sanitary report with COFEPRIS.