Another 140,000 Palestinians were ethnically cleansed between 1967 - 1994
Those leaving the West Bank across the Allenby bridge border crossing to Jordan were required to deposit their identity documents with Israeli officials. In return they were given a card, valid for three years, which could be extended three times for an additional year.
If they stayed abroad more than six months beyond the expiration of the card, Israel deemed them "NLRs" -- no longer resident -- and their right to return was revoked.
"The mass withdrawal of residency rights from tens of thousands of West Bank residents, tantamount to permanent exile from their homeland, remains an illegitimate demographic policy and a grave violation of international law," said Hamoked, an Israeli NGO that filed the freedom of information request.
Some of the 140,000 were later allowed to return, but an estimated 130,000 are still deemed NLRs. "I doubt there is a family in the West Bank that does not have a relative who lost their residency rights in this way," Dalia Kerstein of Hamoked said.
Requests to extend residency rights while abroad nearly always went unanswered, she added.
Saeb Erekat, the former Palestinian chief negotiator whose brother lost his residency rights after leaving to study in the US, described the policy as a war crime.
Israel was "engaging in a systematic policy of displacement ... to change the demographic composition of the occupied Palestinian territories", he said in a statement.
"This policy should not only be seen as a war crime as it is under international law; it also has a humanitarian dimension. We are talking about people who left Palestine to study or work temporarily but who could not return to resume their lives in their country with their families."
The process began at the start of Israel's occupation of the West Bank in 1967 and ended in 1994 when the Palestinian Authority was established under the Oslo accords.
However, the practice of revoking the residency rights of Palestinians in east Jerusalem has accelerated in recent years.
Following the annexation of east Jerusalem, Israel distributed identity cards giving residency status -- not citizenship -- to Palestinians living in the city. They were permitted to apply for Israeli citizenship, but the vast majority refused on political grounds.
However, if they leave the city for more than seven years, their east Jerusalem residency rights are revoked. Israeli citizens are allowed to leave indefinitely without penalty.
Since 1995, Palestinians have also been required to prove their "centre of life" is in east Jerusalem or face having their residency rights revoked.
In 2008, more than 4,500 Palestinians had their east Jerusalem identity cards revoked, compared with 229 the previous year, according to the Association of Civil Rights in Israel.
Richard Falk, then, an investigator for the United Nations human rights council, described this as "the forcible eviction of long-residing Palestinians ... [which] can only be described in its cumulative impact as a form of ethnic cleansing".