Stolen caravan?

I was driving through a neighbouring town here in Germany when I noticed an unusal plethora of UK and Irish registered cars and caravans on a public car park. They obviously plan to stay the night. What particularly caught my eye was a 4x4 with the number plates covered up next to a Fendt Mayfair 650 caravan with a self-adhesive number plate which, judging by its poor condition, had obviously been used several times before elsewhere. I immediately had a sneaking suspiscion that the caravan may have been stolen, so I phoned the police as soon as I got home. They who assured me that they would look into the matter. The 'owners' may think that no-one abroad would register this sort of thing on a foreign vehicle, but it was a bit too obvious for me. As had just got out of my local (German) registered car, they would hardly have become suspiscious at my snooping around the car park, taking a close look at all the caravans closely.