Criminal organizations in Mexico have been using several popular digital assets to buy the raw materials needed to make the fentanyl drug, the US Treasury Financial Crimes Enforcement Network (FinCEN) noted in an advisory report on Thursday, citing four tokens - BTC, ETH, USDT, Monero. The report aims to alert America Financial Group to a network of criminal organizations that produce the dangerous narcotic. According to the report, payments usually end up in the escrow wallets of Chinese providers at cryptocurrency companies, sometimes through secondary money transfer agencies.