A legal dispute is looming over Anne Frank’s diary which many people argue will become copyright free on January 1, 2016, the Volkskrant reports on Tuesday.

The paper says the Switzerland-based Anne Frank Fund, which was set up by her father Otto, does not agree that copyright on the teenager’s diary expires next year.

However, the Anne Frank Foundation, which runs the secret Amsterdam annex Anne and her family lived in during World War II, says copyright does expire in 2016 and is planning to publish a new edition of the diaries.

Legally, copyright expires 70 years after the death of the author. Anne died in the Bergen Belsen concentration camp in February 1945. This, the foundation says, means the diaries will no longer be copyrighted.

However, the Basel-based fund argues that Otto Frank edited the diaries after the war and should be considered co-author. The first publication of the book was in 1947 but Frank did not die until 1980.

A spokesman for the fund, which was set up in 1963, said the dispute is not about the book’s potential earnings, all of which go to charity. ‘The question is nothing to do with money,’ Yves Klugmann told the paper. ‘The fund is run by volunteers. And we consider Otto to be co-author.’

The Amsterdam-based foundation, which was launched by Frank in 1957 to stop the house being demolished, focuses on education.

Legal experts told the Volkskrant it will be up to the courts to decide. However, the fund’s claim that Otto Frank is co-author has no legal status, Amsterdam University researcher Stef van Gompel said. ‘Nor do I think they will succeed in winning recognition for Frank as a co-author is court,’ he said. ‘His contribution was minor.’