Thames Valley Police is appealing for witnesses to a fire at a house in Great Brickhill.
The incident happened at an unoccupied house in Heath Road in the early hours of Wednesday.
Detective Constable Mandy Banfield, from Aylesbury CID, said: “The property has been almost entirely destroyed by the fire. There is a lot of speculation in the village about what has happened and I need people with any information that may help the investigation to come forward.
“The fire service was called at 1.49am but it is believed that the fire may have started up to an hour before that.”
Anyone with any information about this incident should contact DC Banfield via 101. You can also call Crimestoppers, anonymously on 0800 555 111.