He said: "Cannabis should be legalised not just decriminalised because it is comparatively less dangerous than legal drugs alcohol and tobacco."
Iverson now claims to have learned more about marijuana and changed his point of view.
"I don't remember saying that, it's certainly not my position now. That was a view I had in 2003 and a great deal has happened since then. I think it's quite free for a scientist to change his mind when faced with new facts."
Or when faced with a new job opportunity...