It was, without doubt, one of the proudest moments of my life. To stand at the memorial to those who suffered and died at Auschwitz-Monowitz, and pay tribute to the British prisoners of war who worked alongside Jewish slave workers in the IG Farben chemical works, was a deeply humbling experience.

I was there thanks to March of the Living UK, which took nearly 200 young British Jews to this year's Yom Hashoah event and came up with the brilliant idea of holding a ceremony to mark the fact that more than 1,000 British and Commonwealth soldiers were unwilling witnesses to the Holocaust.

The story of E715 - the name given to the Auschwitz PoW camp by the Nazi bureaucrats - has still not been fully told. The prisoners held within screaming distance of the Jewish camp were ordinary men (none above the rank of sergeant-major) who happened to find themselves at the heart of the Nazi killing machine. There have been a handful of individual memoirs such as Denis Avey's bestseller The Man Who Broke Into Auschwitz, but much remains unexplained.

What happened here? We know tantalisingly little. What did these men do to help their fellow human beings? A little food here, a cigarette there? During my visit I had the privilege to meet Freddie Knoller, a Holocaust survivor who had worked at IG Farben. He remembered the kindness of a British PoW who once gave him a single cigarette, valuable currency in the camps. Unfortunately, this exchange was also witnessed by a guard and, as all communication between PoWs and Jews was strictly forbidden, Freddie received a severe beating. He never spoke to a British PoW again.

March of the Living was established 25 years ago to help stem the tide of Holocaust denial. I recognise the importance of emphasising that the Final Solution targeted the Jews of Europe and that, although many others died at the hands of the Nazis, the Holocaust must not be "de-Judaised". It is right to honour the men of E715, but they were not victims of the Holocaust. Their suffering was real, but they received Red Cross food packages, were protected by the Geneva Conventions and were not threatened with extermination. Their situation is not comparable to the Jews in the camp next door. However, they were uniquely placed to witness what went on. They knew about the summary executions, they could hear the sounds of mistreatment and see the physical condition of the "stripeys", as the Jewish inmates were known to them. They could also smell the burning flesh from the crematoria at Auschwitz-Birkenau and those who did manage to speak to Jewish prisoners heard about the "showers".

The British PoWs heard and saw the ‘stripeys’

One profound question remains: did the British PoWs try to get the story out about what was really going on at Auschwitz? Thanks to the work of the American Holocaust expert, Joseph Robert White, we know the word spread to other PoW camps, including Teschen, 50 miles away, where many thousands of Allied prisoners were held. The Red Cross visited Auschwitz in the summer of 1944 and in September reported the concerns of Sergeant-Major Lowe, the British camp leader- or "Man of Confidence" - at Teschen. "Spontaneously, the principal Man of Confidence at Teschen asked us if we were well-informed about the 'shower room'. Indeed the rumour runs that in [Auschwitz] a very modern shower room exists where the detainees will be gassed in series... This was impossible to prove. The detainees themselves did not talk about it."

The Man of Confidence at E715, Charles Coward, always claimed he had tried to get news of the "showers" to the War Office in London via letters home. Tragically, these letters have never been discovered. But how much was the British government told by the Men of Confidence or other PoWs? The Jewish Chronicle has led the campaign for full disclosure of the files held in British archives concerning PoW camp E715. It is essential for a full understanding of the British government's reaction to the Holocaust that we find out exactly what the War Office knew and when.

There is evidence that British prisoners did what they could to help in near-impossible circumstances. Norbert Wollheim, the German-Jewish inmate of Monowitz who led the legal claim for compensation against IG Farben after the war, later described the small acts of generosity he received from the PoWs as "manna" adding: "England can be very, very proud of these men… who proved that, even in Auschwitz… humanity can prevail".