Sergei was an ordinary man who became extraordinary

are repressed and killed. We don’t know if President Putin was a direct beneficiary in the $230m theft or had an involvement in Sergei’s torture and murder, but he is ultimately responsible for the cover-up that ensued.

You don’t have to dig very deep to find numerous other examples. Just two weeks ago Leonid Razvozzhayev, a prominent member of the opposition, was kidnapped in Ukraine by Russian secret policemen, threatened that he and his family members would be killed and then forced into signing a false confession. This follows the arrest and jailing for two years of two young mothers from the Pussy Riot punk group for releasing a 40-second song on YouTube criticising Putin.

According to a major Russian think-tank that advises the president, one out of every six businessmen has been subject to a criminal investigation. The lawlessness has reached epidemic proportions.

Every time reporters or foreign heads of state bring up the Magnitsky story with Putin, however, his retort is that the West has human rights problems as well.

More recently, we have looked for ways to obtain justice outside Russia. In April 2010, we started a campaign seeking to impose visa sanctions and asset freezes against the 60 officials who played a role in this case. It gathered a rapid and unexpected momentum. The American government imposed visa bans and there is legislation going through the US Congress called the Magnitsky Act, which will also freeze the assets of Magnitsky’s killers and impose visa sanctions and asset freezes on other human rights violators in Russia.

The British Foreign And Commonwealth Office announced that from April, human rights abusers would be barred from Britain. It is not yet clear if this will include Sergei’s killers, but it is an important step in the right direction.

In July 2012, the Organisation For Security And Cooperation In Europe (OSCE) Parliamentary Assembly, an influential gathering of parliamentarians from 55 countries, called for all its member parliaments to pass similar legislation banning visas and freezing assets of Russian officials in the Magnitsky case.

Last month, a similar resolution was adopted by the European Parliament calling on the Council of Ministers to enact it.

This is the Achilles heel of the mafia-style regime in Russia. The betrayers of human rights in Iran, Belarussia and North Korea tend to stay at home; the people at the head of the regime in Russia go on holiday to St Tropez and shop at Harrods.

Their aim is to steal money at home and invest it in Western banks and real estate. Now we have a tool to deal with them in the West.

It is not true justice but it gives hope to all those fighting the cause of corruption in Russia.

A play by leading Russian playwright Elena Gremina will help to keep the case in the public eye. One Hour Eighteen Minutes, which will open at the New Diorama Theatre in London on November 16, is based on Sergei’s diaries.

The title refers to the time during which prison guards prevented two civilian medics from entering Sergei’s cell to save him from death. Tom Stoppard will host a gala performance of the show.

Many people ask me why I continue to insist on justice now I have received threats to my own life. The answer is that I have a duty to Sergei.

Most people, if faced with a far lesser hardship than Sergei in custody, would have given in. Sergei was an ordinary man who became an extraordinary hero. If we all could show a fraction of his bravery and fortitude, the world would be a much better place.