The British government will launch an official government inquiry into Nazi concentration camps on the Channel Island of Alderney.

The crown dependency was the only place at which German camps operated on UK soil, but the full scale of the horror that took place there has never before been uncovered.

Now 80 years on, the government will seek to establish how many prisoners were killed on the island.

The government’s envoy on post-Holocaust issues, Lord Eric Pickles, said: “The difference between the estimates is so large, I thought it sensible for everyone to put the facts on the table, for it all to be transparent and for the deliberations to be in the open. 

“It seemed pointless people shouting across at each other. It would be better to have a proper discussion and to bring together a panel of international experts.”

Dame Margaret Hodge - whose family fled Nazi persecution - said she welcomed the inquiry.

She told the Observer: “It is time for the British government and Alderney authorities to finally face up to the horror of what happened on British soil. There can be no more lies and no more cover-up.”

The Channel Islands were occupied by the German army from 1940, with Alderney's 1,400 residents totally evacuated. Thousands of prisoners were brought to the island to construct massive concrete defences against an anticipated invasion.

alderney nazi

Ruins of German fortifications on the island of Alderney (Photo: Getty Images)

Up to 6,000 people, including French Jews, prisoners of war and civilians from eastern Europe, and political prisoners from Germany and Spain were all deported to concentration camps established on Alderney.

Some were reportedly murdered though forced labour, while others were tortured and shot, or sent to extermination camps on the continent.

The scale and extent of the killing that took place there, however, has long been contested by historians.

Researcher Marcus Roberts told the Observer: “There are still many questions about what really went on in Alderney and who knew what. 

“For too long, some have been too willing to look the other way in the hope it all goes away. I hope this review will finally provide answers and some justice for the victims.”

Dr Kathrin Meyer, secretary general of the International Holocaust Remembrance Alliance, said: “This inquiry is a significant step toward telling this important history. 

“Dealing openly and accurately with the Holocaust and the history of the Nazi persecution of other groups in all its dimensions is crucial and we expect the results to go a long way in protecting the facts, no matter how uncomfortable they may be.”