It was a report so graphic and distressing that BBC bosses wanted to suppress it. 

Richard Dimbleby was the first British journalist to report on the horror of Bergen-Belsen when the Nazi concentration camp was liberated in April 1945. 

His voice choking with emotion, the war correspondent described to millions listening on their radios the piles of skeletal corpses, the stench of death and the sight of survivors, some of whom had only days or even hours of life left. 

'I passed through the barrier and found myself in the world of a nightmare,' he told listeners, describing the moment he went into Belsen's main compound in Northern Germany.   

Dimbleby's words - republished to coincide with International Holocaust Remembrance Day - marked the first time that the crimes committed by the Nazis had been revealed to the British people.

But the 10-minute report was actually not broadcast until a few days after the camp visit, because Dimbleby's bosses believed the public did not have the stomach for his words, and nor were they entirely sure that the report was reliable.

But Dimbleby, the father of esteemed broadcasting brothers David and Jonathan, made it clear that he would resign if his words were not aired, and so they were played on April 19, 1945 - four days after the camp's liberation. 

Belsen, which was where the Dutch teenage diarist Anne Frank had died - had originally been set up to house Soviet prisoners of war but was then turned in to a concentration camp - where inmates were forced to work - from 1943. 

It began housing some of the Jews who were among the millions that had been rounded up in Poland, the Netherlands, Hungary and other areas. 

More than six million Jews were ultimately murdered in the Holocaust, most at the network of death camps set up by the Nazis, with Auschwitz-Birkenau in Nazi-occupied Poland being the most infamous.  

Dimbleby entered Belsen - where around 70,000 people died - with the British Army's 11th Armoured Division, which had negotiated a truce with the retreating Germany army. 

The war correspondent had been accompanying troops as they fought their way through Northern Germany towards the defeated, ruined Berlin. 

Inside Belsen when Dimbleby arrived were around 40,000 inmates, many of whom had been starved of food and were seriously ill. 

Diseases including typhus and tuberculosis were rife, whilst there were 13,000 corpses lying unburied. 

He described having been driven around the camp in a Jeep with the chief army doctor. 

'I wish with all my heart that everyone fighting in this war – and above all those whose duty it is to direct the war from Britain and America – could have come with me through the barbed-wire fence that leads to the inner compound of the camp,' he added. 

'Outside it had been the lucky prisoners – the men and women who had only just arrived at Belsen before we captured it.

'But beyond the barrier was a whirling cloud of dust, the dust of thousands of slowly moving people, laden in itself with the deadly typhus germ.

'And with the dust was a smell, sickly and thick, the smell of death and decay of corruption and filth.'

Having passed through the barrier and witnessing the 'nightmare' before him, he went on: 'Dead bodies, some of them in decay lay strewn about the road.

'And along the rutted tracks on each side of the road were brown wooden huts. There were faces at the windows. 

'The bony emaciated faces of starving women too weak to come outside – propping themselves against the glass to see the daylight before they died.

'And they were dying, every hour and every minute.

'I saw a man wandering dazedly along the road then stagger and fall. Someone else looked down at him, took him by the heels and dragged him to the side of the road to join the other bodies lying unburied there. 

'No one else took the slightest notice, they didn't even trouble to turn their heads.'

One girl, a 'living skeleton', was so thin that it was 'impossible' to determine her age, he said. She pleaded: 'English, English. Medicine, medicine.' 

A distraught mother laid her dying baby on the ground at the feet of a British soldier, pleading for some milk. 

And the troops themselves were 'moved to cold fury' by the situation they were encountering, Dimbleby said. 

Men and women who had been distinguished in their lives were seen to have 'long since ceased to care about the conventions and customs of normal life'.

And a sergeant who had been in charge of one of the squads of Nazi SS guards was described as a 'gangling creature with tiny crooked ears' and 'big hands'.

Asked by the broadcaster how many people he had killed, the soldier was said to have replied: "Oh, I don't remember." 

Dimbleby explained to listeners that he had laid out the facts so that they could be 'told without reserve' what had happened at Belsen.

But he reserved his most horrifying account for the last part of the broadcast, describing the 'pit the size of a tennis court' where one end was piled 'to the very top' with bodies. 

He added that the British troops were doing everything they could to save the survivors. 

However, more than 10,000 former inmates died in the days and weeks after liberation. 

Tragically, some died because their bodies had lost the ability to digest the food that was given to them. 

SS guards who had not already fled were put to work picking up decaying bodies and dig burial pits - necessary because of the disease threat - as they were watched by survivors. 

Medical students were sent from Britain to help cope with the shortage of nurses and doctors who were struggling to treat the thousands of inmates that needed care.

With many too weak to survive despite the help they received, it took a month after liberation  before the daily death rate fell below 100 for the first time. 

When the situation was brought under control and Belsen was cleared, it was burned to the ground by soldiers carrying flame throwers and British Churchill Crocodile tanks.

Its destruction was necessary because of the camp's typhus epidemic and louse infestation. 

Speaking to the BBC in October last year, Jonathan Dimbleby, 78, said he had been told by one of his father's close colleagues that 'he had broken down on several occasions' when recording the broadcast. 

He added: 'The BBC at first was reluctant to transmit it, because it wanted corroboration from others. 

'There was no other corroboration immediately available. That so dismayed my father that he said: "If you don't put my broadcast out, I will never broadcast again.' 

Dimbleby returned to Belsen in 1965 - the year of his death from cancer - to mark the 20th anniversary of the former camp's liberation. 

His son added: 'I think the reason he went back was to say: "I have to see it one more time. 

'It was a measure of how extraordinarily important to him it was personally as well as professionally. 

'And, you know, he died a few months later.'