The teenaged stars of the Harry Potter movie will cost Warner Bros $3.6 million (GBP2 million) when they stop filming the new movie for a month to take school exams.

Daniel Radcliffe, 17, and Emma Watson, soon to be 16, must sit Advanced Supplementary (AS) Levels and General Certificate of Secondary Education (GCSE) exams respectively this summer, halting the progress of the fifth movie, HARRY POTTER AND THE ORDER OF THE PHOENIX by a month.

A source says, "Not everyone is going to be paid but Warner Bros are having to factor in an extra GBP2 million into the budget to pay for studio hire and offices."

Radcliffe, who plays HARRY in J K Rowling's blockbuster series, is studying English literature, history, religion and philosophy, while co-star Watson, better known as HERMIONE GRANGER will sit exams for standard subjects including English, maths and science.