Video report by ITV News Arts Editor Nina Nannar
As the celebrity interviewer of his age, Sir David Frost's encounters were must see television in the United States and here in the sixties and seventies - including his famous clash with disgraced American president, Richard Nixon. Must-see but not must-keep, it seems. Half had gone missing. So in a labour of love, one of Sir David's sons has tracked down a secret stash of recordings in an unlikely setting; the Nixon archive. Ironically, they were made for President Nixon himself, so he could study Sir David's technique. Not that it did him much good.