Anne Frank wrote her now-famous diary while she and her family hid in a secret annex behind an Amsterdam canal-side house in an attempt to avoid Nazi occupiers during World War II It has always been theorised that the young Jewish diarist and her family were discovered by Gestapo officers in after a tip off from an unknown informant. Papa has been there. On prostitution, she wrote: Share this article Share The Anne Frank Foundation announced the discovery on Tuesday, saying it helped to explain her adolescent interest in sexuality. Anne Frank on sex and prostitution in her own words In the passage on sex, Anne described how a young woman gets her period around age 14, saying that it is 'a sign that she is ripe to have relations with a man but one doesn't do that of course before one is married. Over eighteen months later she emphasised the important of good and thorough sex education, and she did not understand why adults were so secretive about it. Anne wrote her diary while she and her family spent two years in hiding in an Amsterdam canal-house, in an attempt to avoid Nazi occupiers during World War II. In , the family went into hiding in secret rooms at the back of her father Otto Frank's office building. Otto Frank, the only family member to survive the Holocaust, returned to Amsterdam after the war. The text underneath two taped off pages from Anne Frank's diary reveal risque jokes and an explanation of sex and prostitution A video shows how two pages taped off with brown masking paper from Anne Frank's diary being photographed to reveal her writing The Frank family, originally from Frankfurt in Germany, had left for the Netherlands when the Nazis gained control in the s. Anne, who died in a Nazi concentration camp before she turned 16, would have written the passages aged between 13 and In Paris they have big houses for that. Anne did not let go of the subject. He was given Anne's diary, which had been saved by a family friend, and it was published in , leading to her posthumous fame. By , the Nazis had occupied the Netherlands, leaving the family trapped in Amsterdam. Anne died of typhus in the Bergen-Belsen Nazi concentration camp, shortly before it was liberated by Allied forces in Her uncovered diary texts show that she had gleaned information on the subject of sexuality from her parents, especially her father, from her friend Jacqueline and from books.