The Mexican Navy reported Monday that it had seized nearly 10 tons of concentrated liquid methamphetamine hidden in 11,520 tequila bottles bound for export.  

The interception occurred on Sunday at the Pacific seaport of Manzanillo, Colima, while marines were inspecting 960 cardboard boxes containing what appeared to be tequila bottles. 

 According to the Associated Press, a sniffer dog alerted inspectors to the boxes, which contained liquid the color of añejo tequila.  

After an examination of the liquid by the Navy’s pharmacology and toxicology laboratory, the 750-ml glass bottles tested positive for methamphetamine. 

The bottles contained some 8,640 kilograms (about 19,000 pounds) of the illegal drug. 

The Navy reported that so far this year it has “seized and destroyed approximately 114.3 tons of methamphetamine.” 

In March, the U.S. State Department said it was alarmed by the expansion of Mexican criminal groups, which lead global production and drug trafficking of substances such as methamphetamine, heroin and fentanyl and dominate the import and distribution of such drugs into the U.S.

Mexico has become one of the largest producers of methamphetamine in the world, according to the latest United Nations World Drug Report. The drug is mainly produced in the states of Baja California, Sinaloa, Jalisco and Michoacán.

To import methamphetamine, smugglers often fill windshield washer fluid tanks or other containers in their cars. The liquid meth is then taken to specialized facilities to extract the water and return it to its crystal form. 

With reports from El Economista, AP News,  Infobae, Council on Foreign Relations and El País.