Simmons, who lived in Houston, Texas, died at his vacation home in North Haven, Maine, on August 8, 2010, at the age of 67.

Simmons bases his case on hundreds of internal documents from Saudi Aramco, professional journals and other authoritative sources.

And I still believe that what happened is that the riser blew off the wellhead, and it's hooked onto the rig; so you've got a mile of oil inside that that's pretty light concentrate.

SIMMONS: That's a tiny leak, and what the scientists are saying watching this stain spread – it's now bigger, I gather, than Maryland and Delaware, and several hundred feet thick, and it's gooey stuff – that's NOT coming out of there; they think that it's flowing at 120,000 barrels a day.

SIMMONS: What the research vessel found a week ago Sunday [referring to news reports of May 16, 2010] was this giant plume about six miles (10 km) away, and then this huge layer of goo on the ocean floor... that's almost certain – I mean, maybe it's a natural fracture – I think that's where the wellhead is.The Guardian reported that Simmons was mentioned in a leaked U.S State Department cable dated November 2007: COMMENT: While al-Husseini believes that Saudi officials overstate capabilities in the interest of spurring foreign investment, he is also critical of international expectations.

He stated that the IEA's expectation that Saudi Arabia and the Middle East will lead the market in reaching global output levels of over 100 million barrels/day is unrealistic, and it is incumbent upon political leaders to begin understanding and preparing for this "inconvenient truth."

Al-Husseini was clear to add that he does not view himself as part of the "peak oil camp," and does not agree with analysts such as Matthew Simmons.

[21] An autopsy by the state medical examiner's office the next day concluded that he died from accidental drowning with heart disease as a contributing factor.