So here's an article that at once contains interesting information yet singularly misses the point of it.
Who cares that Cameron appointed someone to run tax collection for the UK who once had a tenuous association with the Cameron family's tax affairs? That's pretty flimsy, right?
Now by contrast, who cares that Cameron appointed someone to run tax collection for the UK who once described tax as "legalised extortion" and who led efforts to campaign against stronger powers for HMRC?
The later seems a much stronger, more pertinent story: you don't need to imply corrupt and seedy goings-on when, in fact, the plain and open truth is that Cameron appointed a head of HMRC who believe that taxation is obligatory only insofar as you can't avoid it. In other words, someone who has the best interests of the Tories and their big-money supporters at heart ... no need for corruption, he really believes in the stuff they want him to do ...