A sacked Pakistani health worker recalled Wednesday how she knocked on Osama bin Laden's door just days before he was shot dead by American soldiers, an unwitting pawn in a controversial vaccination programme set up by the CIA to ensnare the Al-Qaeda leader.

Amna Bibi spoke to AFP while revisiting the site of bin Laden's destroyed home with two other health workers on the anniversary of the American raid. Sacked by the government over the fake vaccination programme, they said they had been dismissed unfairly and demanded their jobs back.

Pakistan arrested surgeon Shakeel Afridi, who was recruited by the CIA to help track down the Al-Qaeda terror leader and was among a total of 18 health workers who were dismissed.

The United States was not 100 percent sure that bin Laden was living in the Abbottabad house when Navy SEALs went ahead with the raid on May 2. British newspaper The Guardian said Afridi was recruited by the CIA for an elaborate scheme to vaccinate residents for hepatitis B, a ploy to get a DNA sample from those living in the house.

"I was assigned to the vaccination of hepatitis B on April 20, and on April 20 Shakeel Afridi came himself to manage the campaign," Bibi told AFP.

"We came to this compound. We knocked at the door for five minutes, but no one opened the door. Then we went into the house in front of Osama's compound and asked for their number, and one girl gave us Tariq's number," she said, referring to one of the men killed in the American raid on May 2 and now known to have been sheltering the bin Laden family.

[Amna Bibi via AFP / Sajjad Qayyum]