Argentinian officials have announced that carfentanil was present in a batch of adulterated cocaine responsible for the death of 24 people. The opioid, which is reported to be 10,000 times more potent than morphine, is restricted for use as a sedative for large animals. Investigations into how the cocaine was exposed to carfentanil are underway.

Source: https://english.elpais.com/international/2022-02-11/drug-used-to-anesthetize-elephants-found-in-adulterated-cocaine-that-killed-24-in-argentina.html