Border Force officers at Dover have seized approximately 9 kilos of amphetamine, worth around £360,000.
Officers stopped and searched a Polish-registered car and found the drugs hidden within the chassis of the vehicle.
The case has now been passed on to the National Crime Agency for further investigation.
The two Polish occupants of the car have been bailed pending further enquiries.
Paul Morgan, Director of Border Force South East and Europe said, "Border Force officers are on constant alert to keep illegal drugs and other banned substances out of the UK.