British actress Emma Thompson is to appear in the next Harry Potter film The Prisoner of Azkaban.
Thompson will play professor Sybill Trelawney
Thompson will play Sybill Trelawney, professor of divination at Hogwarts.
The movie, directed by Mexican film-maker Alfonso Cuaron, is expected to be released next June. It is the third in the Harry Potter series.
"I am very excited to work with Emma," Cuaron said. "She brings such life and spirit to the characters she portrays."
The film will also feature Gary Oldman.
Other actors lined up for the latest film include David Thewlis and Michael Gambon, who replaces Richard Harris as Professor Dumbledore.
Daniel Radcliffe, Emma Watson and Rupert Grint will return to their roles as Harry, Hermione and Ron.
Thompson was an Oscar winner in 1993 for best actress for her role in Howard's End, and in 1996 for writing Sense and Sensibility.
The first two Harry Potter films, directed by Chris Columbus, have proven to be huge successes.
The first film, Harry Potter and the Philosopher's Stone, made more than $317m (£203m) in the US alone, and £63m in the UK.
Meanwhile, JK Rowling's latest book, Harry Potter and the Order of the Phoenix, has so far sold more than 2.9 million copies in the UK alone since it was released in June.