The Duchess of Cornwall praised Anne Frank’s “harrowing memoir” as she met the wartime diarist’s step-sister, Eva Schloss, at a lunch held by the Anne Frank Trust for Holocaust Memorial Day.

Lighting a candle in memory of Shoah victims, the Duchess urged guests at the central London event not to be “bystanders to injustice or prejudice.

“Surely our personal values are measured by the things we are prepared to ignore.

“Let us therefore learn from those who bore witness to the Holocaust, and all subsequent genocides, and commit ourselves to keeping their stories alive, so that each generation will be ready to tackle hatred in any of its terrible forms.”

The lunch marked 75 years since the original publication of the Dutch teenager’s diary, two years after her death in a concentration camp.

Ms Schloss, an Auschwitz survivor, lived in the same apartment building as Anne Frank.

After being freed by Soviet troops Ms Schloss’s mother married Anne’s father, Otto Frank.

She said that tackling discrimination and prejudice required more effort than ever.

“It nearly looks impossible but we must never, never give up.”

Reflecting on the importance of remembrance, Ms Schloss pointed out: “One and a half million Jewish children were lost; often we don’t even know their names. For the future, we have to remember all the victims, not just a few that stand out.”

She revealed that she had never spoken about her experiences during the Holocaust until 1986.

Then, at an event in London, then Greater London Council leader Ken Livingstone asked her to speak.

At first, she wanted to hide “under the table,” but once she began to tell her story, “I haven’t stopped since”.

She said that while she had influenced many people down the years, “it takes much more than that - we have to change governments”.