The BBC showed "basic" journalistic failures in a news report in which it wrongly accused a senior politician of child abuse, an internal investigation has found.
The findings were announced after the BBC's acting director-general, Tim Davie, pledged to "get a grip" of the deepening crisis at the world's largest publicly-funded broadcaster as two more top news executives stood aside.
The investigation into the allegations that a former Conservative party treasurer, Alistair McAlpine, had abused children at a home in Wales in the 1970s found there had been a failure to complete "basic journalistic checks".
The report by the BBC's Scotland director, Ken MacQuarrie, found that journalists on the flagship programme which broadcast the claims had failed to show the politician's accuser a photograph of McAlpine.
These failings were "unacceptable", MacQuarrie said.
He also highlighted confusion about who had the ultimate responsibility for "final editorial sign-off" on the story, which the BBC had to retract after it was shown.
