A Pakistani commission investigating how Al-Qaeda chief Osama bin Laden lived undetected for years in the country has banned foreign travel for everyone involved in the probe, a statement said.
The investigation began after the covert killing of the Al-Qaeda chief by US Navy SEALs at his Abbottabad hideout in May, which took place without Islamabad's prior knowledge, causing a diplomatic rift with the US.
The probe seeks to find out how the world's most wanted man managed to live a stone's throw from Pakistan's top military academy for years, and how America learned of his whereabouts and killed him on Pakistani soil undetected.
Included in the travel ban is Shakeel Afridi, a government surgeon who is being questioned over a free vaccination campaign he reportedly launched in March-April in the neighbourhood around bin Laden's compound.
Security officials in the area believe the doctor may have known about bin Laden's presence in Pakistan and may have shared the information with US intelligence agents before the raid.
"The Abbottabad Commission has imposed a ban on traveling abroad for all persons related to Abbottabad incident including Dr Shakeel Afridi till further orders," said a statement by commission spokesman Adnan Manzoor.
"No such person should be allowed to leave the country without clearance from the Abbottabad Commission," the high-level four-member commission said.
Afridi carried out the vaccination campaign against polio and hepatitis in the northwestern garrison city's Bilal Town where bin Laden stayed for six years, according to US media reports.
His two associates including a female nurse are said to have visited the compound in an attempt to obtain a blood sample from bin Laden, but they were unsuccessful, security officials in the town said.
Local media reports have said the authorities detained Afridi and interrogated him for several weeks following the deadly US raid, but officials have made no comments.