A Pulitzer Prize-winning investigative journalist has claimed that Barack Obama lied about the killing of Osama bin Laden for his own political advantage, and that the former al-Qaeda leader was in fact an unarmed “invalid” when he was shot by US Navy Seals in 2011.

President Obama was accused of making up a number of key details that were fed to the public in the wake of the assassination, including that Bin Laden died in a fire-fight and that the Pakistani government had no role to play in the mission.

Seymour Hersh, whose previous investigations have included the use of chemical weapons by the Syrian government, cited unnamed intelligence officials as part of what he called his “alternative history of the war on terror”.

Writing in the London Review of Books, Mr Hersh claimed that rather than hiding out in a compound in Abbottabad, Bin Laden was in fact being held prisoner by the Pakistani intelligence services when he was killed.

The article quotes “a retired senior intelligence official who was knowledgeable about the initial intelligence about Bin Laden’s presence in Abbottabad”, who said Pakistan had secretly detained the wanted terrorist for years to use “as leverage against Taliban and al-Qaeda activities”.

In the immediate aftermath of the killing, Obama told the media the mission had been a secret incursion into Pakistan and that a small team of Seals fought a dramatic gun battle with men inside Bin Laden’s compound.

But according to Mr Hersh’s source, senior Pakistani officials willingly gave up Bin Laden’s location to maintain good relations with the US and in exchange for a slice of a $25 million reward fund.

They also facilitated the Navy Seals mission by cutting power to the compound and diverting the local military, it was alleged, and had even agreed with the White House upon an elaborate back story where it would be claimed that Bin Laden was killed in a drone strike in mountains on the Pakistan-Afghan border.

The White House has repeatedly insisted that Bin Laden would have been taken alive if he surrendered – but according to the retired official quoted by Hersh, “it was clearly and absolutely a premeditated murder”.

The Seals were given “absolute authority to kill the guy”, the official was quoted as saying, even if they only “suspected he might have some means of opposition, like an explosive vest under his robe”.

Locals and media gather outside the compound, pictured in May 2011, where Osama Bin Laden was reportedly killed in an operation by US Navy Seals (Getty images)

“The truth is that bin Laden was an invalid, but we cannot say that,” the retired official reportedly said.

Mr Hersh also reports that White House claims Bin Laden was still receiving information from and giving orders to al-Qaeda were “lies, misstatements and betrayal”.

“The White House had to give the impression that bin Laden was still operationally important,” he quoted the official as saying. “Otherwise, why kill him?”

The White House is yet to comment on Hersh’s claims. On Monday, Mr Hersh appeared on CNN to defend his article.