The reason why the BBC dropped the Panorama inquiry.

A couple of Tories visited the BBC. One said, "Nice BBC you've got here. Shame if something were to happen to it." Meanwhile, the other one casually knocked a programme off the shelf and said, "Oops," when it smashed to pieces on the floor.

Strictly speaking, this scenario is unnecessary, since the BBC is run by Tory stooges. They're quite capable of censoring any investigation likely to embarrass their lords and masters.