The curious case of the Karpov-Kasparov "agreement".

Mark Crowther reports

On the penultimate day of the General Assembly Andrei Makarov announced he had a letter (which somehow didn't see the light of day until Karpov left Yerevan) signed by Kasparov and Karpov agreeing to a World Championship match.
According to Kevin O'Connell the main points were
1. The match to be for the title of World Champion;
2. The match to be played outside of FIDE and PCA;
3. A special Organising Committee to be set up to oversee the match;
4. The contestants: the "World Champion" and the "FIDE World Champion";
5. Not fewer than 16 games, not more than 20.
6. Procedure for tie-break games.
7. Other technical details.
8. Agreement to be signed by 15 November 1996.
He also says it was signed by both players. The following day after several people had been in touch with him Karpov faxed a 3 page statement to Roman Toran which he read out. Karpov claimed he had never signed any agreement with Kasparov. So is Karpov being disingenuous? Was his signature forged? Or some other explanation. A genuine puzzle.