I keep asking the same question: why, after the war, didn't they look for the heirs?"Mrs Greenberg's story is only one of many. This is the enduring mystery of the Second World War: what happened to the gold, the cash, the jewels, the art stolen by the Nazis, from Jewish victims of the Holocaust, from the coffers of occupied countries and the houses of those who resisted? Towards the end of the war, the US government launched Operation Safehaven in an attempt to track and recover assets the Nazis had deposited in neutral countries in Europe: Sweden, Spain, Portugal, even Ireland, but above all, Switzerland. She approached various banks through the official channels, hoping to find not money but some link to the past, a letter from her father, a photograph album. "I got no reply." She tried again in the 1970s, in 1982 and again last year. "They ask for papers but I have none, everything was destroyed That's why I can't even find out how old I am ...

Mr Kestenberg was shot in Buchenwald in March 1945; Mrs Greenberg does not know what happened to her mother. In 1964, on a camping holiday in Switzerland, Mrs Greenberg tried for the first time to track down the dowry left by her father. He armed his only child with false papers and handed her to the family's dressmaker, who sent Hannah to live with a Catholic in the countryside. "He told me before I left that I'm Jewish, that I have family in Israel and that there will be a nedan, a dowry, for me when I get married, in Switzerland,'' Mrs Greenberg said. "He taught me my Hebrew prayers and my Catholic prayers, and he told me I must say my Hebrew prayers in my mind, but never aloud, that I must go down on my knees and pray the Catholic way until the war is over and he would come to collect me.'' But of course he never returned. Hannah Greenberg's father led her over walls and through cellars, across roof-tops and into the ruins and finally through the gate of the Warsaw Ghetto She doesn't know how old she was, perhaps four or five.