The Jordanian suicide bomber who carried out the worst attack against the CIA in decades in Afghanistan tricked his family, the BBC has learnt.
Humam Khalil Abu-Mulal al-Balawi, 36, killed seven US agents and a Jordanian intelligence officer when he detonated himself at the Khost base last week.
But his friends and relatives had believed the doctor was in Turkey.
A relative told the BBC that the family only realised his whereabouts when they heard news of the attack.
The BBC's Dale Gavlak, in Zarqa, Jordan, spoke to a family member who refused to be identified after being told to remain anonymous by the Jordanian authorities.
By Dale Gavlak, BBC News in Zarqa, Jordan
In terms of reaction to the news the bomber was a double agent, there has been very little reporting in the Jordanian press.
When the body of the Jordanian intelligence officer was returned on Saturday, as he was a relative of King Abdullah, the body was received by the royal family.
A wake was held for the man at a royal palace, but there has been almost no news about it in the papers.
The lack of coverage may highlight that the issue of Jordanian intelligence links to the CIA is so sensitive. It would play very badly with Muslims and Arabs.
He said Balawi had fooled them all about his intentions and his beliefs, telling his family he was travelling to Turkey to join his Turkish wife and children and continue his medical studies.
Instead, he went to Forward Operating Base Chapman, in Afghanistan, where he carried out the worst attack against US intelligence officials since the US embassy in Beirut was bombed in 1983.
The relative cried as he spoke about Balawi, our correspondent reports. He described him as a devout - if somewhat aloof - Muslim who cared for the poor.
Balawi was reportedly recruited by Jordanian intelligence officials when he attempted to enter Gaza as part of a medical team last year.
According to US media reports, he was a CIA double agent whose specific mission was tracking down al-Qaeda's number two, Ayman al-Zawahiri.
The revelation that the man was a double-agent is embarrassing for both the US and Jordan
Frank Gardner, BBC Security Correspondent
Mystery of CIA bomber
Neither the CIA or the US government has confirmed these reports.
According to the Washington Post, Balawi had lured the CIA officers into a meeting at the base's gym with a promise of new information on al-Qaeda's top leadership.