Express: Emergency services rushed to the scene after a “suspicious vehicle” was stopped at a passport control booth on the French side of the border, Lille-based newspaper La Voix du Nord reports.
A source told French radio network France Info the driver of the car had threatened to blow himself up along with his vehicle.
Explosives experts were dispatched to the scene and a security cordon put in place shortly after 1pm local time (noon BST).
The suspect vehicle – a black VW car – was stopped at French passport control, just before reaching the UK border.
France Info reports the driver arrived at the ferry terminal without a ticket or any identity documents and demanded to speak to French President Emmanuel Macron as well as King Mohammed VI of Morocco.
The driver was arrested and the lockdown lifted at around 3pm local time (2pm BST).