Police are searching for a white and red van, that was spotted under 'suspicious circumstances' in Linden Village.
The owner of the Citreon Berlingo had left the engine running, whilst it was being defrosted, in Ivinghoe around 6am on January 8.
When the owner returned to his vehicle, which is white with distinctive red rear panels, it was gone - along with his keys and wallet, which had been left inside.
A vehicle matching this description, but bearing Irish number plates, was then seen in "suspicious circumstances" at 11pm the same day, in the Linden Village area of Buckingham.
Reports say there were three men in the vehicle at the time, one of which is described as white and a large build. There is no description for the other two men.
The van was eventually found in the Bedfordshire area, along with a number of tools, believed to also have been stolen.
Investigating officer PC Dean Kingham, based at Aylesbury Police Station said “I want to speak to anyone that might have seen this van, or can give me a description of the men.
“Enquiries are ongoing to find out who the recovered tools belong to and I will be in contact with the owners when this has been done.
“I would also like to remind residents not to leave vehicles unattended when they are being defrosted. Not only does this provide opportunist thieves a chance to steal it, your insurance company may not pay if it is stolen under these circumstances.”
If you have any information regarding this crime please call PC Kingham on the 24 hour non-emergency number 101, quoting reference number 43180006624.
If you don’t want to speak to the police or give your details you can contact Crimestoppers anonymously on 0800 555 111, or report it online.
Crime prevention advice and information can be found on the Thames Valley Police website.