A SENIOR Republican senator has alleged that Barack Obama’s administration deliberately covered-up details of the attack on a US consulate in Libya that killed four Americans, including the American ambassador.

South Carolina senator Lindsey Graham told CBS’s ‘Sunday Morning’ programme he believed the administration knew that the attack in Benghazi – which took place on the 11th anniversary of the September 11 terrorist attacks – was a coordinated militia assault within 24 hours of it taking place.

He says the administration described the attack as a spontaneous protest gone awry so that voters would think al-Qaeda had been dismantled by President Barack Obama.

Graham said: “Either they are misleading the American people or are incredibly incompetent.”

The White House declined to comment on Graham’s allegations.

It has said previously that an investigation is under way and officials have spoken to the matter as intelligence became available.

The attack resulted in the death of four people, including US ambassador Christopher Stevens.