How Russia is engaged in a battle for its own history

It looks like a prison and in some ways, that is exactly what it has become.

Just a few kilometres from the Kremlin, down on Bolshaya Pirogovskaya Street, lies a squat-looking complex that holds the State Archive.

Inside an austere 10-storey corner-block, you will find a multitude of documents relating to the Russian revolution, the administration of the Soviet Union in Russia and the activities of the police.

For the not inconsiderable sum of 10,000 roubles (£120), Sky News was given permission to film inside and we were surprised when one staff member told us that Russia's security police the FSB had recently been to visit.

They were unhappy with the general set-up revealed the archivist.

"They said it was too easy to access some of the documents. In the past, relations of people killed (during the Soviet period) could read files about their loved ones. Now those documents are being summarised for them instead," he said.

The FSB's trip to Bolshaya Pirogovskaya is just the latest sortie in the battle for Russian history - a fight for the collective memory waged by the government on one side and a small number of academics, civil society organisations, officials and victim's relatives on the other.

It is thought that as many as 50 to 60 million people suffered from the political purges, expulsions, massacres and manufactured famines between 1917 and 1956.

Repressive acts authorised by Joseph Stalin - the diminutive, club-footed Georgian who led the country for much of that period - may represent the largest yet most poorly understood crimes of the 20th century.

Poorly understood because human rights groups like Memorial are finding it increasingly difficult to find out what is held in the national archives.

"Everything is starting to move backwards now," said Memorial co-chair Yan Rachinsky.

"Documents belonging to the FSB and MVD (Soviet Interior Ministry police) are very difficult to get hold of because the government has extended the period that they will remain top-secret. It's difficult because we don't even know what these documents are about."

One set of documents that have been made public detail a 1948 investigation into Panfilov's 28.

Just about everyone in Russia knows how 28 soldiers under General Panfilov's command made a heroic last stand against a column of German tanks in November of 1941.

Yet the military judge who conducted the inquiry found that a group of war-time journalists made the story up. There was a battle in the area, but not the way the men from the Red Army's newspaper said it happened.

The documents were published online by the head of the state archive, Sergei Mironenko - an act for which he was later fired.

What is more, Mr Mironenko's boss (Andrey Artizov) was dragged on national television in April and told by President Putin that the national archive would now come under his direct control.

Under Mr Putin, Russia's role in defeating Nazi Germany in what is known here as the Great Patriotic War has become a central part of Russian identity.

"Putin says we should be proud of our history and the things that followed are influenced by that idea," said Mr Rachinsky.

"But I think we should admit history as it was and try not to make it look better than it was."

There is a price to pay for those who dispute the official narrative.

We met Vladimir Luzgin, an auto-body painter from the Russian city of Perm, thousands of miles from home in Prague.

He has decided to seek political asylum in the Czech capital after he was prosecuted and fined for reposting an article detailing how Nazi Germany and the Soviet Union carved up Poland at the beginning of the Second World War.

The state prosecutor said Mr Luzgin had distributed "knowingly false information" - and the judge agreed, making him the first person in Russia to be convicted under a new law prohibiting the "rehabilitation of Nazism".

Mr Luzgin, who says the FSB raided his flat looking for evidence, has refused to pay the 200,000 rouble (£2,500) fine.

He said: "It's natural that I don't accept my guilt because it's a fact that Germany attacked Poland and it's a fact that a little later Soviet troops entered Poland.

"I was sentenced for stating a historical fact. How can I proven guilty?"

His conviction is part of a pattern say critics, a wide-ranging assault on Russia's historical memory.

The facts are out there, in the hands of victims' relatives and on the shelves of the State Archive's 10-storey tower, but many worry they will never see the light of day.