Used to smuggle drugs seems by far the most likely. Mummies would have the benefit of being ostensibly fragile, valuable, and repellent to most. That’s a trifecta drug smugglers would hope for, in terms of evading deep inspections.
> “Since the initial work of Balabanova et. al., other studies have revealed the same drugs (cocaine, nicotine, and hashish) in Egyptian mummies, confirming the original results."
