I think it was Richard Dimbleby too. I remember seeing the clip in the 1970's. I think it was repeated on several occasions because it was so funny ( I suppose funny because people were taken in by it, but at the time, as PRINTMISS says, spaghetti was not so popular and not so well known).
I’m finished my festival poncho
How does a 'lived experience' differ from an 'experience'?