Haifa, The National - In December 1948, eight months after the start of the war that created Israel, Khalil Beidas locked the door to his Jerusalem home's library, a three-metre-high, floor-to-ceiling collection of more than 6,000 books that had been his most prized asset.

The 75-year-old prominent Palestinian intellectual then escaped to Lebanon, where he died less than a year later - partly, his grandson says, because of the emotional pain from the loss of his library.

Amid the battles in Jerusalem, Hagop Melikian, an Armenia-born Palestinian businessman, also fled along with his wife from their apartment. He left a private library with dozens of books, including a German-translated complete set of Shakespeare plays and a 19th-century German encyclopaedia, through which he would not flip again. The tens of thousands of books owned before the war by wealthy Palestinian families like those of Beidas and Melikian is only a sliver of what Palestinians lost when they were forced to flee what is now Israel.

Still, the issue of the books' whereabouts has gained controversy after a 2011 revelation by an Israeli researcher that about 6,000 books that had belonged to the Palestinian cultural elite living in West Jerusalem before the 1948 war are languishing in the basement of the National Library of Israel in Jerusalem and marked "abandoned property".

The discovery was followed last year by a documentary, The Great Book Robbery, which charged that the "plunder" of private Palestinian libraries by Israeli librarians in the war's aftermath helped destroy the then-vibrant Palestinian cultural renaissance.

Now, Palestinian activists are making a legal bid to get the books back. Palestinian history experts like Mahmoud Yazbak of Israel's Haifa University say their return could significantly shed light on the pre-war Palestinian intellectual awakening that had been centred in Jerusalem.

"Jerusalem was the Palestinian intellectual and cultural capital of that time," said Mr Yazbak. "Most of Palestine's cultural heritage was lost along with their houses. The loss is very big, much more than we could ever imagine."

Following the 1948 war, a race began for the private possessions of about 28,000 Palestinians who had lived in West Jerusalem - at the time one of the region's wealthiest communities. Competing against the widespread looting of Palestinian homes that was taking place throughout Israel, librarians rushed to collect 30,000 mostly Arabic books from the houses of Jerusalem's prominent Palestinian families, according Gish Amit, an Israeli doctoral student who discovered the Palestinian collection in the Jerusalem library by stumbling upon documents on it in the library's archive.

Mr Amit, 40, says most of the 30,000 books collected are lost, and only about 6,000 have been catalogued.

Tens of thousands of other Palestinian books were collected in cities such as Haifa or Jaffa but their fate remains unknown.

The most prominent book-owner was Khalil Sakakini, a poet and scholar who had escaped to Egypt, where he mourned the loss of his books in his published diaries, wondering if they were transferred to a library or used to "wrap onions" at a grocery store.

Mr Amit says Israel initially intended to return all the books, but that policy appears to have changed. Indeed, while the books were at first marked with the names of their rightful owners, those marks were erased in the 1960s and replaced with the label AP, or abandoned property. Nevertheless, he says, proof of ownership is still possible through handwritten dedications, names and notes on book covers and pages.

While the collection is closed to the public, individual books can be accessed by special request. The Israeli finance ministry, which includes the Custodian of Absentee Property, a body formed after the 1948 war which seized Palestinian refugees' abandoned property, including the books, declined to comment on why the books have not been returned.