Anne Frank
A picture of Anne Frank lies in front of her memorial stone on the grounds of the Bergen-Belsen MemorialGetty

Anne Frank's Diary of a Young Girl has been published online amid a copyright dispute. A powerful memoir of the Holocaust, the diary was first published in Dutch posthumously in 1947.

The Anne Frank Fund, based in Basel, Switzerland, holds the rights to the publication of the diary that chronicles Frank's hiding for two years (1942-1944) with her family during the Nazi occupation of the Netherlands. The Fund told AFP that it had sent a letter threatening legal action if the diary was published online.

According to the Fund, copyright for posthumous work extends 50 years after the publication date. Since a version of it was published in 1986 by the Dutch State Institute for War Documentation (NIOD), it is under copyright at least until 2037, it said.

However, University of Nantes lecturer Olivier Ertzscheid and French parliament member Isabelle Attard, who made the diary available for free online on 1 January, said under a 1993 European law, any book whose author or authors are dead for 70 years become a public property.

Frank died aged 15 years old at Bergen-Belsen concentration camp in Nazi Germany in 1945, over 70 years ago. And that's enough time that her work got in the public domain, they said.

"70 years after the death of Anne Frank, because this time is enough and because it is legal, this diary should be in the public domain. It belongs to everyone. And it is up to each to measure its importance," wrote Ertzscheid. The duo have both posted Frank's diary online on their personal blogs in its original Dutch.

They said putting the work in public domain would only make the writer more known and give the public knowledge worth knowing. "Dear Anne Frank, have the intelligence to finally give you the light you deserve, one that deserves your journal, that of the public space. Welcome to the light, dear Anne," Ertzscheid wrote.