Alexander Solzhenitsyn, the man who exposed Stalin's brutality, dies aged 89

Russian literary giant Alexander Solzhenitsyn - the writer who bravely exposed the horrors of Soviet Communism to the world - has died aged 89.

The author, poet and historian, who was awarded the Nobel Prize for Literature in 1970, suffered either a fatal stroke or heart failure at his Moscow home, according to Russian news reports.

Solzhenitsyn shot to prominence for his unflinching depictions of the brutality of Stalin's network of Soviet gulag deathcamps, in which more than 20 million people died.

His accounts of the shocking inhumanity of the Bolshevik Communists appalled the West and saw him stripped of his Soviet citizenship.

Forced into exile for 20 years, he settled in West Germany and later the USA, and from his base there continued to be a thorn in the side of the Communist government.

The Gulag Archipelago, his best-known work which was banned in Russia but published in the West in 1973 - is a devastating detailed history of Lenin's and Stalin's reign of terror.

He was awarded the Nobel prize -which he was famously banned from collecting - "for the ethical force with which he has pursued the indispensable traditions of Russian literature"

Solzhenitsyn's son Stepan said last night that his father died of heart failure, at the home he shares with his second wife Natalya at 23.45 local time.

Other reports quoted literary sources as saying he had suffered a stroke.

Russian President Dmitry Medvedev sent his condolences to the writer's family, a Kremlin spokesman said.

Solzhenitsyn and his wife Natasha in Vladivostok, 1994, the year he returned to Russia after being expelled from the USSR in 1974

Born in Rostov, Solzhenitsyn's early years saw the new Soviet union devastated by hunger and violence.

A maths and physics graduate, he served as an officer with the Red Army in World War Two and was decorated for his courage.

But denounced in 1945 for criticising Stalin in a letter, he spent the next eight years doing back-breaking hard labour in a network of prison camps, vividly described in "One Day in the Life of Ivan Denisovich.".

Disillusioned with the regime, the experience moulded into one of the most prominent dissidents of the Soviet era.His major novels uncover the hidden world of prisons, labour camps, food shortages and summary justice he experienced.

Solzhenitsyn bravely wrote about the brutality of Stalin's network of gulags

Best-sellers in the West, they destroyed any remaining sympathy for the Communist regime among left-wing intellectuals, and inspired millions with the message that personal courage could defeat a totalitarian regime.

His books were initially welcomed by the Russian leader Khruschev who was keen to distance himself from the Stalinist terror, but after his ousting, his works were banned and he began facing KGB harassment.

Solzhenitsyn as a captain in the Soviet Army in 1944

When summoned for deportation in 1974, he made a damning written statement to the authorities: "Given the widespread and unrestrained lawlessness that has reigned in our country for many years, and an eight-year campaign of slander and persecution against me, I refuse to recognize the legality of your summons.

"Before asking that citizens obey the law, learn how to observe it yourselves. Free the innocent, and punish those guilty of mass murder."

The West offered him shelter and accolades, but Solzhenitsyn was vocal in his criticism of Western culture for what he considered its weakness and decadence.

Returning to his home country as a hero in 1994, he was lived quietly in Moscow, where his writing has continued to criticise Western materialism and Russian bureaucracy.

But his later works did not generate the same interest from the West. His disdain for capitalism and disgust with the new generation of Russian tycoons was unfashionable, and in recent years he has faded from view, although his popularity has increased under Putin.

Solzhenitsyn is survived by his wife and three sons.