In a report published in the London Review of Books, Pulitzer Prize-winning journalist Seymour Hersh has accused the Obama administration of using “cherry-picked intelligence” regarding an attack on Aug. 21 using chemical weapons in Syria that killed more than 1,300 people and served as evidence for an argument in favour of a military strike against President Bashar Al-Assad’s regime.

In the report titled, "Whose Sarin?" — Hersh refers to a top-secret June cable sent to the deputy director of the Defence Intelligence Agency that said al-Nusra, an extremist group fighting in the Syrian civil war could acquire and use sarin. But the Office of the Director of National Intelligence and the Office of the Defense Intelligence Agency could not find the document in question, even when given its specific codes.

The administration, he claims, buried intelligence on the extremist group and never considered it a suspect in the sarin attacks, so much so that Samantha Power, the US ambassador to the UN, told a press conference: “It’s very important to note that only the [Assad] regime possesses sarin, and we have no evidence that the opposition possesses sarin.”

While it is not known whether Power’s office was provided the highly classified al Nusra intelligence, her comment reflected the narrative that the Obama administration was putting forward.

Given that information, Hersh claims that “Obama did not tell the whole story” when stating with certainty that Assad had to be responsible, crossing a so-called "red line" that makes a military response imperative.

The journalist who is best known for breaking the Abu Ghraib prison scandal in 2004 cited interviews with intelligence and military officers as well as American intelligence documents leaked by former NSA contractor Edward Snowden and reports by the Washington Post that have been published based on those documents.

Hersh has also cited reporting done by the Post on a “secret sensor system” that he wrote would have been expected to detect Assad's regime preparing for a chemical attack in the days that lead up to it.

The report claims that as opposed to the impression give to the public, the administration was learning about the attack at roughly the same pace as the civilians were.

Hersh writes that daily intelligence briefings in the days before and after the gas attack did not make a single mention of Syria, even as videos and photos of the attack were spreading across the Internet.

Though President Barack Obama ultimately decided not to strike Syria, Hersh argues that the administration made a public case for military action by saying that Assad’s regime alone was responsible for a poison gas attack in the outskirts of Damascus, despite there being intelligence to the contrary.

If the allegations hold to be true, it will create yet another controversy for the Obama administration and recall the Bush administration’s tainted legacy over its decision to go to war in Iraq over cherry-picked intelligence.

The civil war is now in its third year and has killed than 120,000 people, while the Organisation for the Prohibition of Chemical Weapons (OPCW) conitues its work to destroy the Syrian regime's chemical stock pile.

The OPCW, which won the Nobel Peace Prize this year, has been directed by the United Nations to oversee the destruction of the Syrian government’s chemical weapons.