Since December 9, the man – thought to be in his forties – has carried out a series of robberies in which he has pointed what is believed to be a fake revolver at the person behind the cash register, and then made off with a pile of pastries without paying.
In each instance, no-one has been hurt and the value of the pastries has varied between £7 and £17.
The police are hunting the thief, who is still at large and could strike again at any moment.
He seems to favour bakeries in Parisian suburbs.
If you see anyone stepping off the Eurostar who looks shifty and is carrying an unusual amount of croissants, be sure to report it.