Today, in Moscow, there begins the trial of a 37-year-old accountant by the name of Sergei Magnitsky. Mr Magnitsky is accused of tax offences dating back perhaps 10 years.

What is astounding about this case is that Magnitsky is not only innocent of all charges. He is also dead. He died in prison in November 2009, after almost a year in which he was kept in squalor, denied family contact and deprived of medical treatment — detention that culminated in a savage and fatal beating by his captors.

It says something about the Russian state that it should now put this ghost on trial, in what must be the most grotesque parody of legal proceedings since the animal trials of the Middle Ages. It says something about Russian justice that Magnitsky — and his family — are now being persecuted by the very legal establishment whose corruption he exposed. And that message is that there are no lengths to which the Russian kleptocrats will not go to protect themselves and their ill-gotten loot, and to grind the faces of their enemies.

Magnitsky was a whistleblower. He uncovered a scam, a gigantic criminal conspiracy by which the Russian police and tax officials colluded with the judiciary and mafia to steal millions from the Russian state. When he refused to change his evidence and give in to his interrogators, they killed him – only eight days before they would have been legally obliged to bring him to trial or let him go.