A newly leaked database detailing the complicity of the government in widespread illegal construction in West Bank settlements will be used to help Palestinians file lawsuits over what they say is their lost land, rights group Yesh Din said Friday. The classified database, compiled by the Defense Ministry and obtained by Yesh Din, shows that government agencies and private companies building settlements in the West Bank widely ignored Israeli law, in many cases seizing land that belongs to Palestinians. It also demonstrates that the government has long been aware of the lawbreaking and has kept it secret. More than 30 settlements were built in part on land owned by Palestinians, the report shows, and in three out of every four settlements some construction was conducted without proper permits. In one settlement, Elon Moreh, the report says, 18 houses were built on private land. In another, Efrat, a park and a synagogue were built on private land, and in a third, Ariel, a college was built without legal approval. In other settlements, roads, cell phone antennas, basketball courts and neighborhoods were built illegally. The report focuses on the some 120 West Bank settlements officially authorized by the government since Israel captured the territory in the Six Day War. The Defense Ministry would not comment on the report. Michael Sfard, Yesh Din's legal counsel, called the information a "severe indictment" of Israel's military and government. Israeli authorities are "systematically violating international law and the property rights of Palestinian residents," Sfard said in a statement. The group said it intends to use "all legal means" to challenge the violations listed in the leaked database, including filing civil suits and appealing to Israel's Supreme Court. Yesh Din will begin running ads in Palestinian newspapers to encourage people to take legal action, and will also offer legal counsel, the statement from the group said.