Oil reserves at Israel's Meged 5 oil site have been upgraded to 3.53 million barrels - more than doubling previous estimates - extending over 125 to 250 square kilometres. The only problem is that much of the oil lies under the West Bank, and so does not belong to Israel at all.

The oil drilling site, operated by Givot Olam, an Israeli oil exploration company, sits northwest of Ramallah on the 'Green Line' that formally separates Israel and the occupied Palestinian territories. Palestinian officials report that Israel has moved its 'separation wall' to give Givot Olam clear access to the site.

Israeli researcher Dror Etkes, who follows Israeli activities in the West Bank, believes the Meged site lies just "a few dozen metres" inside Israel. "The reality is that Israel is enjoying the economic fruits of the occupation by exploiting resources that belong to the Palestinians", he says.

The Oslo accords require Israel to coordinate any exploration for any cross-border natural resources with the Palestinian Authority, and reach agreements on how the benefits are divided. But the Palestinian authority says drilling is going forward without any such agreement.

The Meged oil field, said Ashraf Khatib of the PA’s negotiations support unit, was part of Israel’s "theft of Palestinian national resources". He added: "The occupation is not just about settlements and land confiscation. Israel is also massively profiting from exploiting our resources. There’s lots of money in it for Israel, which is why the occupation has become so prolonged."

Gidon Bromberg, director of Friends of the Earth Middle East, said: "If there are reserves of oil under the occupied territories, then absolutely Israel must talk to the Palestinian Authority about any exploration being undertaken to extract them."

But experience to date suggests that the PA may get little or no benefit from its oil. A dozen Israeli firms are estimated to have taken $900m worth of stone from quarries in the West Bank. In 2011 their right to do so was asserted by Israel's Supreme Court, despite the provisions of the Hague Convention which prohibits such resource exploitation in occupied territories.

Israel and its settlements within the West Bank also take some 90% of water drawn from West Bank aquifers, leaving only 10% for the Palestinians.

Jonathan Cook is an award-winning British journalist based in Nazareth, Israel, since 2001. A longer version of this story is available: Israel to drill for oil in the West Bank.