Jacques Chirac, the French president, said he was "a bit surprised at the leak" and said he had asked Michele Alliot-Marie, the defence minister, to investigate its source.

In Washington, US officials said they had no reason to believe that bin Laden was dead and said that they had no knowledge of the leaked French document.

Condoleezza Rice, the US secretary of state, told reporters in New York: "No comment, no knowledge," when asked about the French article.

Secret Document

On Saturday, the French regional newspaper l'Est Republicain, published what it said was a copy of a French secret service document that cited an uncorroborated report from the Saudi secret services that al-Qaeda leader had died.

The DGSE, French foreign intelligence service, had distributed the document, dated September 21, to Chirac and other senior French officials, the newspaper said.

"According to a usually reliable source, the Saudi services are now convinced that Osama bin Laden is dead," it read.

"The information gathered by the Saudis indicates that the head of al-Qaeda fell victim, while he was in Pakistan on August 23, to a very serious case of typhoid that led to a partial paralysis of his internal organs."

"His geographic isolation provoked by constant fleeing is  believed to have made medical assistance impossible [and] on  September 4, 2006, the Saudi security services received preliminary information of his death."

It said the Saudis were "waiting to obtain further details and  notably the exact place of burial before officially announcing the news."

The Saudi interior ministry was not available for comment.

Internet reports

"This information is in no way whatsoever confirmed," Chirac said when asked about the document.

The Washington-based IntelCenter, which monitors al-Qaeda communications, said it was not aware of any similar reports on the internet.

"We've seen nothing from any al-Qaeda messaging or other indicators that would point to the death of Osama bin Laden," said director Ben N Venzke.

The last time the IntelCenter says it could be sure bin Laden was alive was June 29, when al-Qaeda released an audiotape in which he praised al-Qaeda in Iraq leader Abu Musab al-Zarqawi, who was killed in a US air strike in Iraq earlier that month.

Officials in Pakistan and the US, which has made capturing bin Laden a priority, were unable to confirm the document's account.