This is question we get asked on a very regular basis.
Is the registered keeper of the vehicle the owner of the vehicle.
The registered keeper is the name on the V5 (log book),
this is not proof of ownership of the vehicle.
Proof of ownership is only proven by a bill of sale or purchase receipt.
This is why it is very important when buying a secondhand vehicle to ensure that, a signed receipt of ownership and the money paid for the vehicle is clearly stated, dated and signed by both parties.
The City of London Bailiffs vehicle re-possession unit.