An Israeli human rights group claims that even under Israel's own rules, one of the longest-established and best-known Jewish settlements in the West Bank is unlawful.
All Jewish settlements in the West Bank are considered illegal under international law, because the West Bank is supposed to be Palestinian territory, but the Israeli government only accepts that some of the smaller ones do not belong there.
Now the human rights group B'tselem has published a report that says more than 60% of the Ofra settlement, established in 1975 near Ramallah on the West Bank, sits on land registered as being owned by Palestinians.
BBC Middle East Correspondent Tim Franks quotes B'tselem spokeswoman Sarit Michaeli as saying that the group's research removes any legal prop for Ofra to exist under Israeli law.
She argues that Israel has set certain criteria for what qualifies as a legal settlement, and "Ofra does not fulfil these criteria. "And the most important one - the fact that most of the land in Ofra is in fact privately owned by Palestinians - means that Ofra qualifies as the largest unlawful outpost in the West Bank."
The authorities in the settlement, which has a population of 4000, dispute the findings.