Until Ekaterina Mikheeva saw her husband Fedor led away in chains to an Arctic prison camp, she did not think the Russian criminal justice system could sink so low.

Mr Mikheev had taken a risk that few others dared take, and it cost him 11 years of freedom: he had pressed charges against a group of high- ranking policemen, claiming they had kidnapped him in 2006.

The case is one of several that illustrate the fearsome reach of Russia’s security services. Once feared for their efficient repression of ideological dissidents, their reputation now inspires just as much dread as before, for what Russians call reiderstvo, or raiding. Corrupt police nowadays often work hand in glove with organised crime gangs, targeting vulnerable businessmen with investigations and arrests as a way to shake them down for money or take over their assets.