A freshly dead individual of the giant squid Architeuthis dux, presumably mutilated by a predator of bigger or comparable size, is reported from the south-western Indian Ocean in proximity to Reunion Island. The species was identified from body and beak morphology and validated genetically. The dorsal mantle length (DML) estimated from beak measurements (lower rostral length, LRL) varied between 2153 and 3060 mm depending on the allometric equation used. The Architeuthis dux individual described here is the biggest giant squid ever reported for the region.