Hold onto your broomsticks, Harry Potter fans. IMDB reports that Gary Oldman may not be returning in the role of Sirius Black in Harry Potter and the Order of the Phoenix. The movie has already begun filming and Oldman, who played Sirius in the last two films, reportedly has yet to be signed for a reprise in Order of the Phoenix. The character of Sirius plays a crucial role in the storyline, so presumably someone will have to play the part. I can't imagine Warner would cast someone else in the role, so hopefully whatever issues are preventing that from happening will be resolved fairly quickly. Mugglenet, which is probably a more reliable source than IMDB on all things Potter, says they talked to Warner Bros, and that Warner confirmed negotiations are still underway with both Oldman and David Thewlis, who plays Professor Lupin.