A JCB digger was deliberately set on fire at an industrial estate in Walton last month.
Police are appealing for witnesses to the arson on Friday, December 20, at Total Metal Recycling at Weylands Industrial Estate between 10.30pm and 11pm.
The digger, which officers believe was targeted deliberately, is now unusable and valued at about £20,000.
The arsonist was wearing a dark hooded top with a white motif on the front, light coloured trousers or jeans and white shoes.
It is believe he may have been carrying a black plastic JD Sports drawstring bag and a white plastic container.
Any witnesses of anyone with information should call Surrey Police on 101, quoting reference 45130008142 or Crimestoppers on 0800 555111.