Jerusalem - Israel is locking away millions of official documents to prevent the darkest episodes in its history from coming to light, civil rights activists and academics have warned as the country's state archives move online.
They claim government officials are concealing vital records needed for historical research, often in violation of Israeli law, in an effort to avoid damaging Israel's image.
The Israeli army has long claimed to be the "most moral" in the world.
Accusations of increased secrecy come as Israel marks this week the 49th anniversary of the 1967 war, when it seized and occupied Sinai Peninsula, Gaza Strip, West Bank, and Golan Heights.
Many of the records to which access is being denied refer to that war and the first years of Israel's military rule over Palestinians in Jerusalem, the West Bank and Gaza.
Menachem Klein, a politics professor at Bar Ilan University, near Tel Aviv, said researchers needed such documents to gain a clearer picture of events half a century ago, the goals of policymakers, and human rights abuses. "We have gradually been able to expose some of what happened in 1948 [the war that established Israel], but there is still very little available to help us understand the 1967 war," he told Al-Jazeera.
The entire history of Israeli society and its conflict with the Palestinians is to be found in those archives. It is impossible to understand and write about that history without access.
As part of its commemorations this week, the state archives published testimony by military commanders from 1967. However, local media noted that whole pages had been censored on "security grounds".
Nonetheless, some of the declassified material was revealing. Uzi Narkiss, who headed the army's central command at the time, suggested that he and other commanders hoped to ethnically cleanse most of the territories under cover of fighting. He told fellow officers: "Within 72 hours we'll drive out all the Arabs from the West Bank".
The campaign to open up Israel's archives is being led by the Akevot Institute, a group of Israeli human rights activists, lawyers and researchers trying to document the history of the Israeli-Palestinian conflict. In a new report, Point of Access, they note that only 1 percent of 400 million pages of documents have been made public.
Most of the files should have been accessible after 15 years. In many cases, Akevot says, the classified status of documents has expired, but they have still not been made public. Reasons for denial of access are rarely given.
In other instances, documents that were already declassified - some of them decades ago - have been re-sealed and are now unavailable.
Despite the mounting secrecy, historic war crimes are still coming to light.
In March the largest known massacre of Palestinians by the Israeli army during the 1948 war that founded Israel - what Palestinians call al-Nakba - was exposed, in spite of official efforts to keep the atrocity under wraps for nearly seven decades.
The gag was effectively ended with the publication of a soldier's letter in the Haaretz newspaper, detailing the execution of hundreds of Palestinian men, women and children at the village of Dawaymeh, near Hebron. "The entire history of Israeli society and its conflict with the Palestinians is to be found in those archives," Lior Yavne, co-author of the report, told Al-Jazeera. "It is impossible to understand and write about that history without access." He added: "In practice, most of Israel's archives are permanently closed."
According to Akevot, Israel has exploited a new programme to digitally copy existing paper files to increase secrecy.
Archivists are currently scanning and uploading documents to create a comprehensive database - a project that is likely to take more than 25 years. The archive's website went live in April.
However, the public nature of the database means hundreds of thousands of national security files have been submitted for the first time to an official body known as the military censor. Until now its powers had been largely restricted to oversight of the Israeli media, said Yavne.
The censor is reported to be refusing to release many of the documents, redacting others and reclassifying as secret many records that were previously available to researchers.
A growing backlog of tens of thousands of files that need to be reviewed has also blocked access to researchers, according to Akevot.
Requests to see documents can be denied if they damage national security or foreign relations, or violate privacy. Yavne said access to records after the specified time restriction had expired was regularly refused without legal authority. Files appeared to be withheld if officials feared they might "highlight human rights violations or shed light on sordid affairs."
The report notes that the records of government decision-making belong to the public but are treated as "a secret to be kept from it".
The current emphasis on concealment contrasts with the late 1980s, when parts of the archives from the 1948 war were opened.
A handful of Israeli historians, most notably Benny Morris, Ilan Pappe and Avi Shlaim, revealed that much of Israel's official history of the state's founding was based on misinformation.
These "new historians" unearthed evidence of wide-scale massacres of Palestinians, rapes and forced expulsions. They also showed that common assumptions about the war - such as that Palestinians had been ordered to flee by their leaders - were later inventions by Israel to minimise international criticism.
One Israeli academic, Shay Hazkani, has estimated that up to a third of records relating to the 1948 war that were declassified have been put under lock again. Given the large number of documents, many had yet to be examined by researchers.
Nur Masalha, a UK-based Palestinian historian who exposed evidence in Israel's archives of expulsion, or "transfer", policies against Palestinians between 1948 and 1967, told Al Jazeera the clampdown on access to documents was part of wider internal repression in Israel.
It reflected, he said, Israel's mounting concern at the connections being made between Israel's past and present atrocities. "Israel has faced growing international condemnation for its war crimes in Gaza, and at the same time Palestinians, including those inside Israel, have become more determined to focus attention on the Nakba."
Some of the most highly classified records - which have been under lock for 70 years - are due to be made public in less than two years' time. That would turn the spotlight on the most contentious events from Israel's founding. However, according to Akevot, no preparations have been made by Israel's most secretive security agencies, the Shin Bet intelligence service and the Mossad spy agency, to release their archives.
The report says access "is expected to be denied" for the foreseeable future. Yavne said the Shin Bet had already ignored a commitment to make available sections of its archives after 50 years.
Those documents would shed light on Shin Bet policies in the state's early years, when a fifth of Israel's population belonging to the Palestinian minority were placed under a military government.
Details of this period would be embarrassing both because of the harsh treatment of Palestinians during military rule and because the template of the military government was later exported into the occupied territories, said Klein.
Archive documents might expose the Shin Bet's detention and torture practices, its use of blackmail and entrapment to recruit informants, and its harassment of Palestinian leaders. "The Shin Bet has always operated beyond the law," he said.
The Israeli prime minister's office, which oversees both the archives and the Shin Bet, declined to comment.
Yavne said Akevot, which was established 18 months ago, was assisting academics and researchers who were often afraid to speak out against the mounting restrictions. "They are worried that if they are seen to be criticising the archive policy, they may face even more restricted access," he said.
He added that Akevot was creating an alternative database of documents to help researchers to understand the history of the Israeli-Palestinian conflict.
Among the top-secret documents recently unearthed by the group is one revealing a government order immediately after the 1967 war to remove the Green Line, marking Israel's internationally recognised borders, from all maps used in Israeli schools.
Klein said the aim was to "root into Israelis' minds the idea that the occupied Palestinian territories are part of Israel" to make returning them more difficult.
Other classified documents from the period show that Israel's chief adviser on international law, Theodor Meron, warned that the Geneva Conventions applied to Israel's behaviour in the occupied territories. Israel has publicly always denied that it is bound by the conventions. There has been a similar spate of revelations about the 1948 war.
In January Haaretz reported that the archives were still refusing access to a transcript of a cabinet meeting in 1949 in which ministers discussed the widespread desecration of churches the previous year.
The discussion, however, could be reconstructed from other sources.
The Foreign Minister of the time, Moshe Sharett, is recorded as saying the Israeli soldiers had behaved in ways "fit for savages"- a reference to their defecating in churches and looting icons. Sharett suggested paying the Vatican large compensation to "buy their silence".
Israeli military correspondent Amir Oren recently wrote that archival evidence showed that the current spate of Israeli soldiers executing Palestinians was not a new phenomenon.
The 1948 war, Oren wrote, had "launched the catalogue of murder, rape, looting, contempt for human life" by the Israeli army.