When the disgraced ex-US president Richard Nixon, conceded he had deceived the nation and "let down" his people, David Frost was assured a place in television history.
Now, for the first time, Sir David has revealed just how much it cost him, financially, to secure the interview. He believes he would now be some £37m richer had he not humbled Nixon on TV, but says he has no regrets.
Writing in a new book, Shooting Stars, Sir David described it as "one of the riskiest ventures on which I've ever embarked.
"After Richard Nixon's resignation from the presidency in 1974, I became determined to interview him in depth, to resolve the questions left unanswered by his grimly unapologetic departure. American broadcasters were eager to do just the same thing, and to secure Nixon's participation I had to outbid them. That meant making him an offer of $600,000, or around £3m in today's money. The only way I could raise the cash was to use the one real asset I owned, a 5 per cent stake in London Weekend Television. I sold my shares and threw the money into the venture. If I'd kept them, they would have been worth £37m when Granada took over LWT in 1994. But I would still have made the same decision."