Speaking for the first time since his arrest, Shakil Afridi told Fox News he did not think he needed to escape after the killing but was then kidnapped by Pakistan's ISI intelligence agency.
He said the ISI regarded the US as its worst enemy, and had tortured him.
Dr Afridi is understood to have been contacted by phone in jail in Peshawar.
Prison officials contacted by the BBC were taken by surprise by reports of the interview, but did not rule out that a phone could have been smuggled into his cell.
The Fox News interview raises many questions. Dr Afridi's lawyer wonders how a journalist could set up a phone interview with him in a maximum security prison cell. A jail official speculates that if anyone could smuggle a phone to him, it could only be one of the close relatives that visited him in jail twice in August.
But many ask why the relatives - a brother, two sisters and a cousin - would undermine their own rather hard-won right to meet him periodically after an initial ban?
The question is did Dr Afridi actually say the things he's reported to have said in the interview? If so, why, given that this could translate into further problems for him and his family?
One explanation is that Dr Afridi believes he's in a desperate situation, and that keeping the story alive may be his best defence.
He was sentenced to 33 years in jail in May for funding and supporting a militant group, but correspondents say it is generally acknowledged he is being punished for helping the US Central Intelligence Agency (CIA).
The interview was published on the eve of the 11th anniversary of the 9/11 attacks on the US, and came as current al-Qaeda leader Ayman al-Zawahiri confirmed the death of another senior figure in the network, Abu Yahya al-Libi, in a US drone strike in Pakistan's tribal areas earlier this year.