The discovery, on the eve of Kim’s two-day summit with Donald Trump in Hanoi, was made after Dutch authorities flagged up the suspicious route and records of a Chinese-owned container ship, Nebula.

The Russian vodka, contained in 3,000 boxes, had been recorded as being due for unloading in China, via the ports of Hamburg and Rotterdam.

When officers sought to retrieve the container from the ship’s hull, it was found to be concealed and hemmed in by the fuselage of an aircraft also due to be exported to China.