According to the Directorate-General for National Security, investigators found 31 tons of cannabis and almost 200 kilograms of cannabis resin in a warehouse near Tangier on Wednesday.
The drugs were therefore hidden in dummies of fruit and vegetables and were supposed to be exported disguised as food.
Officers found more sacks and bales of hash in a large refrigerated trailer.
A 61-year-old man was arrested.
He is suspected of having "connections to a criminal network operating in the international drug trade".
Morocco is one of the most important hashish origins in the world.
Authorities seized 191 tons of cannabis resin last year alone.
Last year, the country legalized the therapeutic use of cannabis.