Police identified the man as Gary Brooks Faulkner and described him as being of sound mind, although suffering kidney problems and high blood pressure.
They say he arrived as a tourist in the Chitral district near the Afghan border, checked in at a local hotel and was given a security escort. This is customary in the mountainous area that borders on Afghanistan’s Nuristan province, a stronghold of insurgent groups linked to bin Laden’s Al-Qaeda.
But he disappeared on Sunday night and was later found 14 kilometres from the Afghan-Pakistani border.
Police say the man told them that he wanted to locate bin Laden and his friends because the 9/11 attacks on New York and Washington had caused colossal losses to the US.
“We presume he wanted to kill them,” local police officer Mumtaz Ahmad Khan told the AFP news agency.
The US consulate in the provincial capital, Peshawar, was informed on Tuesday that a US national had been arrested.