A childhood friend of Anne Frank's sister made a surprise appearance at a Jewish Book Week talk by the young diarist's cousin, Buddy Elias.

Inge Parish, 87, of north west London, said she had been moved to speak about her friendship with ten-year-old Margot Frank, after hearing Mr Elias describe his childhood with his cousins.

The audience gasped as Mrs Parish, née Jacobowitz, described how she lived a few doors down from the Frank family on the same square, Merwedeplein, in Amsterdam. Her family had fled Frankfurt in 1932, a year before the Franks, also from Germany, moved to Amsterdam.

She said: "We were very friendly and played together. Of course, I do remember Anna too, but when you're ten, you don't like to play with six-year-olds. Margot and I played stamp collecting: we were always in and out of each others' houses".

The Jacobowitz family evaded the Nazis, moving from Amsterdam to the Sudetenland and then to Palestine, before arriving in England in 1945.

"My father was very forward-thinking, we moved every time just before the Nazis arrived," Mrs Parish said. She lost aunts, uncles and grandparents in the Holocaust.

"I got the book 'Diary of a Young Girl' out of Golders Green library in the early 1950s and I thought 'Good heavens, I know these people'. I got really excited. But I never really told anyone, just a few friends. I decided to go to the talk because Buddy Elias is Anne Frank's cousin, the last direct relative, and he must have known the place we grew up. I wanted to talk to him more but I had to leave before he was finished signing books. I hope I can be put in touch with him"

Mr Elias said he felt Margot was sometimes forgotten because of her famous younger sister. "She was a wonderful girl, but quieter, very intelligent."

Margot, too, had apparently kept a diary. His wife Gerti Elias said: "We think she put it away in a drawer in the house, and the furniture was sold to another family, who just threw it away."

Mr Elias, a former champion ice-skater, spoke at the event, chaired by Gillian Walnes of the Anne Frank Trust, about his book Treasures from the Attic - a collection of letters, documents and photographs of the Frank family, discovered and painstakingly organised by his wife, Gerti. The newly-published book has been written as a novel, describing the family pre- and post-Holocaust, by German novelist Mirjam Pressler.

Mrs Elias said: "I had more than 10,000 pages of documents and photographs, which began in the 19th century, to sort through."

The papers include Mr Frank's desperate letters to his family in Switzerland as he searched for his daughters after leaving Auschwitz. The first thing the Eliases heard, from when the Franks went into hiding in 1942, was a telegram after Otto was released from Auschwitz. Mr Elias said: "It was from the Red Cross and it said 'we are all safe and well'." Of course we thought he meant the whole family.

Later they received a further message from Otto, knowing his wife was dead, but hoping for news of his daughters. It read: "I am physically well but it is all too upsetting for me to describe at present. All that matters is that I see the children again."

In another letter he describes going to look at the lists of those missing, and seeing the names Margot and Anne Frank with two small crosses next to them - and realising that his daughters were dead.

● Writer and film-maker David Cohen will be making a previously unscheduled appearance at Jewish Book Week this weekend.

Mr Cohen has written extensively about Sigmund Freud. In his latest two books on the father of psychoanalysis, The Escape of Sigmund Freud and Freud on Coke, Mr Cohen tells the story of how Freud escaped from Vienna.

He did so with the help of a so-called "good Nazi", Anton Sauerwald, who organised the removal of all of Freud's belongings from the Austrian capital, including the original analytic couch, now on display in the Freud Museum in Hampstead.

Freud's experiments with cocaine form the subject of Freud on Coke.

The talk will take place at 2p.m. on Sunday March 6.