Accountancy firm PwC has held onto its prized Oscars role despite the high-profile blunder at last month's awards - but new protocols are being introduced, including a ban on mobile phones backstage.

Film academy president Cheryle Boone Issacs sent an email to academy members yesterday after a meeting the previous night in which the added controls were agreed, according to an Associated Press report. As well as the ban on phones, the academy is bringing in a third balloting partner and PwC's US chairman will provide oversight. The partners will also have to attend the Oscars rehearsals.