Jimmy Savile's abuse could have been stopped if people had listened to "the small voice standing up against authority and celebrity", the BBC director general has told ITV News.
Lord Hall said there was "enough out there" at the time for people to respond "had they thought about it".
"There were things that were being said in the press about Savile, there were rumours around the organisation," he said.
"If people had spoken one to the other, if things had been investigated properly, if the small voice standing up against authority and celebrity had been listened to then maybe something could have happened back then."
Lord Hall, who has apologised to the victims, said the BBC had "let them down"
He added: "For me, now the most important thing is to say we got it wrong, we let you down and we must act to ensure this can never happen again."