IRREPLACEABLE film has been stolen from a film company trying to make a Bollywood movie in the region.
Thieves also took more than £5,000 worth of equipment as film-makers unloaded equipment in Middlesbrough.
A spokesman for KK Films said the theft may put off other film companies from coming to the North-East.
The film crew was unloading a vehicle in Waterloo Road, at about 7.45pm on Sunday, when an opportunist thief grabbed a black and white bag, containing three cameras, four lenses and other photographic equipment.
However the biggest blow was the loss of three weeks of film of footage taken in Yarm, Whitby and Scarborough.
A spokesman said: "We've used local actors and dancers and thought we could promote this area. This is not only a major blow to us but it may put off other people from coming here."
Equipment taken from the Toyota carrier were a Polaroid camera, Nikon F90x, Nikon 401, four lenses and a Kodak film. Anyone with information is asked to call police on (01642) 303126 or Crimestoppers on 0800 555111.
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