Could the Koran pre-date Muhammad?

Earlier in the summer there was great excitement in academic circles about the discovery of a Koran hidden away at Birmingham University which - so carbon dating suggested - might have been written while the Prophet Muhammad was still alive. As we reported on the World at One at the time that seemed to offer confirmation of the traditional Islamic account of the religion's origins. Now it seems the document could be even older than that and according to the Times newspaper some scholars are suggesting it means the early history of Islam will have to be rewritten.
Tom Holland, author of In the Shadow of the Sword and Dr Sajjad Rizvi, Director of the Institute of Arab and Islamic studies at the University of Exeter discuss the text.