A reliable source has confirmed that the Dursleys are to return for Order of the Phoenix and that Harry Potter does indeed save Dudley from Dementors - just as in the book.
Arabella Figg witnesses the act and Harry will be on trial at the Ministry - also just as in the book.
Warner Bros has not yet commented.
Madame Bones and Mundungus Fletcher have roles in the film, though WB has not yet released information on who has been cast.
We will keep you informed as we hear more!
UPDATE: CBBC Newsround has now confirmed that the Dursleys wil be back. They also inform us that Amelia Bones and two of
Dudleys gang members have been cast.
The only thing we are still awaiting is confirmation about Mundungus Fletcher.