Cash for Honours may seem like it's gone, but it is by no mean buried. Apparently the Cabinet Office has admitted that it holds no records of negotiations it, Downing Street and Scotland Yard had when Blair was interviewed by them.
It's generally believed that Dowing Street told the Police that if he was interviewed as a suspect he would have to resign, but sadly we're never going to really know by the sound of things. The Press Association put a FoI request in to the Cabinet Office for the correspondance and was told that none could be found in "paper or electronic" records.
The Cabinet Office are now refusing to comment on whether records did exist and were subsequently deleted and/or shred. A spokesman told PA, "All we can say is that, for the purposes of the Freedom of Information Act, the information requested is not held".