The BBC's Panorama is to launch an unprecedented investigation into its own affairs in an effort to get to the bottom of how Martin Bashir obtained his notorious interview with Princess Diana. John Ware, one of the Corporation's most respected journalists, has been commissioned to create a special edition of the show which will scrutinise his former colleague and the BBC over the interview, once hailed as the scoop of the century. The investigation, which is likely to be highly embarrassing for both the show and the BBC, could be broadcast next year, sources told The Mail on Sunday – with Mr Ware told to leave 'no stone unturned'.