Years of rooting out drugs at the Brazilian seaport of Santos had given customs inspector Oswaldo Dias a good nose for suspicious cargo. A shipment of secondhand diggers,  bound for Europe late in 2019, seemed fishy.

So on the morning of November 18, Dias sent the machinery through a scanner, which revealed a strange mass lodged inside one of the excavator’s yellow arms. He hopped up for a look and saw cracks in the metal and a dodgy paint job. Dias called for a blowtorch.

Inside, he found 158kg of cocaine, destined for the Belgian port of Antwerp...