Osama bin Laden's 12-year-old daughter has reportedly told Pakistani investigators that her father was captured alive by United States special forces and then shot dead in front of his family.
The al-Arabiya network reported the claims as CIA director Leon Panetta admitted that the Navy Seals who raided bin Laden's compound in the town of Abbottabad on Monday made no great effort to persuade him to surrender.
"The authority here was to kill bin Laden," Panetta told PBS television.
"Obviously, under the rules of engagement, if he had in fact thrown up his hands, surrendered and didn't appear to be representing any kind of threat, then they were to capture him. But they had full authority to kill him," Panetta said.
Panetta later told NBC television that the opportunity to capture bin Laden alive "never developed".
John Brennan, the chief US counter-terrorism adviser, said the American commandos were told to assume bin Laden was wearing a suicide vest, and must be killed, unless he was naked when they found him.
The assault team sent into his compound would have accepted surrender only if they could be sure he had nothing hidden under his clothing, meaning his fate was sealed as soon as he was found in his bedclothes.
The news came as President Barack Obama announced the US would not release "trophy" pictures of Osama bin Laden's body.
Under pressure to provide concrete evidence of bin Laden's death, Obama said: "You will not see bin Laden walking on this Earth again."
Obama said he decided not to release photos of the body because it could have incited violence and been used as an al-Qaeda propaganda tool.
"I think that given the graphic nature of these photos, it would create some national security risk," Obama told the CBS programme 60 Minutes.
It was also revealed yesterday that bin Laden had €500 ($940) in cash and two telephone numbers sewn into his clothing in case he needed to make a quick escape from his compound.
Panetta said bin Laden believed "his network was strong enough [that] he'd get a heads-up" before any US strike against him. He suggested that bin Laden's confidence might have been the reason his compound was only lightly guarded.
It may also explain why bin Laden was not armed when he was killed during the operation.
There have been conflicting accounts from Washington on the details of the operation, raising suspicions that the Seals had indeed been on a shoot-to-kill mission.
The White House said initially that bin Laden had used his wife as a human shield and had been armed. But, in fact, a woman killed during the operation was not his wife and the al-Qaeda chief was not carrying a weapon.
Al-Arabiya reported that bin Laden's daughter, Safia, was one of eight women and children taken from the high-walled compound.
It said that Safia and her mother, who was shot in the leg and is believed to be bin Laden's fifth wife, had been taken to the garrison town of Rawalpindi for medical treatment and to be debriefed by Pakistani intelligence.
There were other differences between Saifa's account of what happened and that of the White House.
According to al-Arabiya, Safia told her interrogators her father was shot dead at the start of an operation that took 40 minutes, slightly longer than expected, after one of the Seals' three Black Hawk helicopters crashed to the ground because of a technical fault.
The network reported that bin Laden was dragged to a helicopter after being shot dead.
Officials believe a Yemini woman captured with members of the bin Laden household might have been bin Laden's personal doctor.
The 54-year-old al-Qaeda leader suffered from kidney problems.
A Pakistani official challenged the US account of a gun battle at the compound, telling Al-Arabiya: "Not a single bullet was fired from the compound at the US forces and their choppers," he said.
Reuters news agency published photographs on its website which it said showed three men lying in pools of blood in bin Laden's compound but with no weapons.
The photos, which Reuters said were taken by a Pakistani security official who entered the compound soon after Monday's raid, show two men with blood streaming from their ears, noses and mouths.
The official, who wished to remain anonymous, sold the pictures to Reuters.
Based on the time-stamps on the pictures, the earliest one was dated May 2, 2.30am (local time) - approximately an hour after the completion of the raid in which bin Laden was killed. Other photos, taken between 5.21am and 6.43am show the outside of the compound and the wreckage of the US helicopter.
Reuters said it was confident of the authenticity of the purchased images because details in the photos appeared to show a wrecked helicopter from the assault, matching details from photos taken independently on Monday.
Reuters also said the pictures were taken in sequence and were all the same size in pixels, indicating they had not been tampered with.
Pakistani security officials said they did not recover any arms and explosives during their searches of the compound on Monday and Tuesday.
"There was no bunker or tunnel inside the house and that's why I don't understand why the world's most wanted man would have decided to live here," a senior official said.
Pakistani leaders rejected suggestions that bin Laden had been given sanctuary by the country's powerful security apparatus.
But the Afghan Government said Pakistan must have known he was living in Abbottabad, echoing international suspicions about Islamabad colluding with its supposed enemy.
"Not only Pakistan, with its strong intelligence service, but even a very weak government with a weak intelligence service would have known who was living in that house in such a location," said General Mohammad Zahir Azimi, a Defence Ministry spokesman.