WikiLeaks is now turning the heat on the oil industry.

The whistleblowing website has unearthed confidential cables from the US embassy in Saudi Arabia that show the world’s largest crude oil exporter may not have enough reserves to prevent escalation of oil prices.

The cables urge Washington to take seriously a warning from Saad al-Husseini, former head of the Saudi oil exploration monopoly, Aramco. Between 2007 and 2009, al-Husseini gave the US embassy proof that the kingdom’s oil reserves are overstated by 300 billion barrels—nearly 40 per cent.

The revelation comes as oil price soared in February to over US $100 a barrel. Analysts expect Saudi Arabia and its OPEC partners would pump more oil if rising prices choked demand. But the cables reveal oil production in the kingdom is almost at its optimum and is likely to fall after 2012.