Osama bin Laden lived in plain sight for almost a decade and was once even pulled over for speeding but not apprehended, an official report into his killing said on Monday.

The report, leaked to Qatar-based broadcaster Al-Jazeera, which circulated it late on Monday, offers fascinating details about life on the run for the world's most wanted man - including his habit of wearing a cowboy hat to avoid being spotted from above.

Written by a judge-led commission that the Pakistani government set up shortly after US special forces killed bin Laden in 2011, the 336-page report is based on interviews with 201 sources, including members of his family and various officials.

In one testimony showing how close bin Laden came to being captured, "Maryam", the wife of one of his most trusted aides, recounted how his car was stopped by Pakistani police in the Swat region.

"Once when they were all ... on a visit to the bazaar they were stopped for speeding by a policeman," the report says. "But her (Maryam's) husband quickly settled the matter with the policeman and they drove on."

To avoid detection from the sky, bin Laden took to wearing a cowboy hat when moving about his compound in the city of Abbottabad, his wives told investigators.

If he felt ill, he treated himself with traditional Arab medicine, and "whenever he felt sluggish he would take some chocolate with an apple", the report says.

He led an austere life, overseeing the religious education and play of his children and grandchildren "which included cultivating vegetable plots with simple prizes for best performances".

The inquiry's findings, which have not yet been officially published, include evidence of incompetence at almost every level of Pakistan's security apparatus. The report is also fiercely critical of the "illegal manner" in which the United States conducted the raid.

CIA spies tracked down bin Laden to the northwestern town of Abbottabad, where he was shot dead by US Navy SEALs on May 2, 2011, during a dramatic raid near Pakistan's military academy.

"The US acted like a criminal thug," says the report by the Abbottabad Commission.

The report contains dramatic details of the US helicopter raid recounted by the al-Qaida chief's family.

Bin Laden had retired to his room with the youngest of his three wives, Amal, when they were awakened by what "sounded like a storm" shortly after midnight. They rushed to the balcony, "but it was a moonless night and pitch dark".

Later, when Amal saw a US soldier pointing his weapon at bin Laden from the landing of their bedroom, she rushed at him as the soldier shouted "No! No!" and shot her in the knee.

After the raid, US forces made off with belongings including computer hardware, but also personal effects such as gold and bin Laden's will.

AP-AFP