Movie bosses at Warner Bros are set to lose an estimated $3.6 million (GBP2 million) this summer (06) as the teenage stars of the Harry Potter films sit their real-life exams.

Filming on the fifth Harry Potter film, HARRY POTTER + THE ORDER OF THE PHOENIX, will grind to a halt in May (06) to allow Daniel Radcliffe and Emma Watson to prepare for and take school exams - at a cost of over $3 million.

A studio source says, "Warner Bros have to pay for studio hire and offices even when there's nothing being filmed."