A book which claimed the Princess of Wales was killed by security forces is being made into a movie, industry website Screen Daily has reported.
Princess Diana and Dodi Al Fayed died on 31 August 1997
Hidden Truth will be based upon Jon King and John Beveridge's book Princess Diana: The Hidden Evidence, which blamed the CIA and FBI for her death.
The £2.8m UK thriller will be produced by Educating Rita's William P Cartlidge with filming due to begin this spring.
No-one has yet been cast, executive producer Len Evans told Screen Daily.
The film is being made by Vision In Production, based at Pinewood Studios in Buckinghamshire, it reported.
Princess Diana and her lover, Dodi Al Fayed, died in a car crash in Paris in 1997.
An inquiry into her death, ordered by royal coroner Michael Burgess, is being conducted by former head of the Metropolitan Police Lord Stevens.
Last month Lord Stevens said the inquiry was "far more complex than any of us thought".