Is it true that the guy who started 'Paul is Dead' admitted to making it all up?

So on some Beatles video there was a heated debate over the REAL Paul McCartney being alive or not, right? Well someone said they had a biography about Paul McCartney, called Paul McCartney A Life, and they said in the book that the guy who started the whole conspiracy said he completely made it up? I was just wondering if that was true because if it was then why would people still be debating about it??