About a tonne of cocaine with a street value of approximately £100m has been found hidden in a shipment of fruit.
The Class A drug was found in pallets on a ship that had arrived at the Port of Dover from South America on Tuesday.
The National Crime Agency (NCA) said the discovery was linked to the infiltration of an encrypted messaging service used by criminals.
Two men arrested on suspicion of importing Class A drugs have been released under investigation.
'Misery to communities'
Nikki Holland, the NCA's director of investigations, said the "huge seizure" had deprived criminals of a "valuable commodity that would have been sold to fund further serious and organised criminality".
The investigation - involving the NCA and Police Scotland - is linked to Operation Venetic, which began after the encrypted messaging service Encrochat was infiltrated by law enforcement agencies.
Angela McLaren, Police Scotland's Assistant Chief Constable, said the discovery of the haul in Dover represented a "massive setback for serious and organised criminals" who "bring misery to our communities".
A 40-year-old man, arrested in Brentwood, Essex, and a 64-year-old man arrested in Glasgow, were questioned and released under investigation, the NCA said.