I had to look up what a "cloned vehicle" is. Never heard of this, but it's what you might suspect. A sign of organized crime, I'd say.
A cloned car is a vehicle that has been given a new identity.
Criminals find an exact match of a car they have stolen - with the same make, model and colour - and copy the identity of the legitimate vehicle.
To make the vehicle they have stolen appear legal, they’ll put on false number plates. They may also use a duplicate or stolen V5C logbook. This is a document issued by the Driver and Vehicle Licensing Agency (DVLA) which would normally be your proof of ownership. Finally, they may change the vehicle identification number (VIN), which is intended to serve as the vehicle’s unique fingerprint, and is normally found on the driver's side at the corner of the dashboard where it meets the windshield, or by driver's side door post.
With such sophisticated techniques used by fraudsters, it means that even if the buyer runs an online background check on the car, then the details may appear to be in order
https://www.ageas.co.uk/solved/your-car/how-car-cloning-works–and-a-new-trick-to-beware-of/