BBC News | EUROPE | Red Army rapists exposed

But the book has been condemned as an "act of blasphemy" by the Russian ambassador to the UK and its conclusions have also been rejected by a prominent Russian military historian.

Mr Beevor, whose previous book Stalingrad became a best-seller, says in Berlin alone it was estimated up to 130,000 women were raped, of whom up to 10,000 committed suicide.

One woman was raped by 23 soldiers.

Mr Beevor said he was shocked by what he found during his research of German and Soviet archives.

He said the widespread rape suggested "there is a dark area of male sexuality which can emerge all too easily, especially in war, when there are no social and disciplinary restraints."

He said the Soviet hierarchy turned a blind eye, and even condoned the rape as a form of revenge for what the German Army - the Wehrmacht - had done during Operation Barbarossa.

One district commander told a group of German women who were seeking his protection: "That? Well, it certainly hasn't done you any harm. Our men are all healthy."

'Bonding process'

Mr Beevor said: "As the Red Army example shows, the practice of collective rape can even become a form of bonding process."

The book has naturally aroused controversy with the Russian Ambassador to Britain, Grigory Karasin, describing it as "lies and insinuations".

But Mr Beevor said the book's claims, while uncomfortable, were backed up by documents which he had found in the Russian state archives.

"The rape of German women was previously known from German archives but I believe this is the first time the fact that Soviet citizens were raped has been published in the West," he told BBC News Online.

He said many people in Russia were still struggling to come to terms with what the Red Army did during the war.

Mr Beevor said: "I was shaken to the core when I discovered that soldiers raped female prisoners of war.

He said women became "carnal booty" during the war.

The Wehrmacht had abducted many Russian and Ukrainian girls and set them up in "military brothels".

The Red Army, for its part, had engaged in an "alcohol-induced frenzy of sadism and humiliation".

'Out of control'

He told BBC News Online: "One has this image of the Soviet state and the Red Army as being extremely disciplined but in the first four months of 1945 their soldiers were completely out of control."

Professor Rzheshevsky, who admitted he had only read excerpts and had not seen the book's source notes, said: "Information on the number of raped and killed women is based on victims' and witnesses' accounts, some excerpts from interviews and other such sources."

He said Mr Beevor's use of phrases such as "Berliners remember" and "the experiences of the raped German women" were more suitable for pulp fiction, than scientific research.

Professor Rzheshevsky said considering what the German Army had done in the Soviet Union the Germans could have expected an "avalanche of revenge".

'Humane soldiers'

But he said that did not happen and added: "The majority of soldiers and officers of the Soviet Army and the allied armies treated the local population humanely."

Professor Evan Mawdsley, a historian from Glasgow University, said it was not the first time women had become "carnal booty" in time of war.

Professor Richard Overy, a historian from King's College London, said the Russians had never faced up to the atrocities committed by the Red Army.

He said: "Partly this is because they felt that much of it was justified vengeance against an enemy who committed much worse, and partly it was because they were writing the victors' history."

Antony Beevor is featured in a documentary, The Battle For Berlin: Timewatch, which will be shown on 10 May at 2100 BST on BBC Two.