“The police got their man after a nine-year vendetta,” one friend of Damian Green is quoted as saying this week. This is perhaps a slight oversimplification – Green was ultimately brought down by his own words, through what he described in his resignation letter as “statements that were misleading” about whether he had been informed by the police that they had found pornographic images on his computer.

I wrote at the start of the month that “We don’t know what Green did or did not do.” Oddly enough, given the fact an investigation has just concluded, on the original allegations that mostly remains the case. The Cabinet Office declined to rule on either the Kate Maltby allegations (they described her account as “plausible”, but went no further) or the allegation that he viewed pornography on his work computer, instead finding him in breach of the Ministerial Code for being dishonest about that knowledge of what the police told him they had found. He has gone as a result – having been ordered to do so by the Prime Minister.

However, even had Green been found triply guilty by the Cabinet Office – of inappropriate behaviour towards Maltby, of viewing pornography on his work computer, and of giving untrue statements about the police having told him they found pornographic images – the concerns I raised previously about the actions of the police would still stand.

Their target undoubtedly sealed his own fate by failing to be honest, but that does not change the fact that the conduct of the police throughout this saga has been disgraceful and deeply troubling.

Counter-terrorist police should not have been deployed to try to plug a political leak in the first place, particularly in a case that turned out not to have any criminal merit.

Those police should never have raided an MP’s office, rooting through the files of constituent correspondence and goodness knows what else.

Had they tried to do so, they should not have been allowed to by the Commons authorities.

Having done so, they should not have interested themselves in material that was legal and completely irrelevant to their inquiry.

Having breached fundamental policing principles by taking such an interest, individual officers should certainly not have retained in their personal possession data about the inquiry and other material found in a search, even once they retired.

And having done all of the above, those retired officers should never have felt it appropriate to then use the information they gleaned in an already dubious search in order to run a PR campaign against a politician whom, for whatever reason, they disliked.

This issue is raised by the case of Damian Green, but it is not really about him. You might disapprove of him as a person. You might dislike his politics. You might disapprove of him as a person and dislike his politics. But if the police can misuse their powers to publicly harm someone as powerful as Green, close to the very top of politics, then just imagine what they could do to you, or anyone else, if this behaviour is allowed to pass.