The new Harry Potter film has broken a record set by its predecessor, The Chamber of Secrets, by taking £11.5m in three days at the UK box office.
Prisoner of Azkaban was released on a half-term bank holiday
The Chamber of Secrets took £10.8m in its opening weekend in 2002 but was beaten by The Prisoner Of Azkaban, which opened in the UK on Monday.
The third film based on Harry Potter books, it opens in the US on Friday.
According to website Screen Daily, the Prisoner of Azkaban made £5.03m on the first day of its UK release.
And it is estimated to have taken £14.3m in its first four days of release.
The UK release of the third Harry Potter film was tactically brought forward to coincide with a bank holiday and the first day of the school half-term holidays.
It still stars Daniel Radcliffe as Harry
Directed by Mexican film maker Alfonso Cuaron, Prisoner of Azkaban sees actor Daniel Radcliffe reprise his role as Harry Potter, alongside previous co-stars Emma Watson (Hermione Granger) and Rupert Grint (Ron Weasley).
It also stars Richard Griffiths as Uncle Vernon, Julie Walters as Molly Weasley and Gary Oldman as Sirius Black.
With a darker atmosphere than the first two films, it sees boy wizard Harry battle Sirius Black, who allegedly betrayed his parents to their murderer, Lord Voldemort.
The movie drew an estimated 510,000 admissions nationwide on its French opening day, said film giant Warner Bros.
This compares with 237,146 French preview admissions and 397,174 first-day admissions for Chamber Of Secrets in 2002.