Updated

The long-awaited retrial of the Pakistani doctor who helped the CIA pinpoint Usama Bin Laden was postponed due to security concerns in the wake of a church bombing that targeted Christians in Peshawar.

After nearly two-and-a-half years in prison, the retrial would have marked Shakil Afridi’s first public appearance. Last month, a senior judicial official overturned the 33-year prison sentence and ordered the retrial, saying the person who originally sentenced Afridi was not authorized to hear the case. Afridi was convicted of terrorism-related charges, but it is widely believed his imprisonment was a result of his collaboration with the U.S. establishing the presence of terror kingpin Bin Laden in an Abbottabad compound prior to the Navy SEAL raid that killed him.

Sources also attributed the adjournment to the prosecution’s insistence that the retrial pick up where the last trial left off. Afridi’s defense wants to reset the entire trial, and has little faith in the new judge, who it believes is under the sway of Pakistan’s notorious ISI spy agency, sources told Fox News. The court adjourned the case until sometime next month.

Afridi’s sentence was overturned Aug. 29, but he has remained in prison since. He was abducted by Pakistani officials in May 2011, weeks after the Bin Laden raid, in a case that has led to strained relations between the U.S. and Pakistan.

Afridi was convicted a year later of conspiring with Islamic militants in Pakistan's Khyber tribal area by giving them money and medical treatment. Both Afridi's family and the militants have denied the allegation.

Afridi was tried under the Frontier Crimes Regulations, the set of laws that govern Pakistan's semiautonomous tribal region. Anis, who ordered a retrial, is a commissioner under the regulations.

In July, FoxNews.com reported that Pakistan is preparing a proposal to swap Afridi for a notorious female neuroscientist and suspected Al Qaeda operative being held at a federal prison in Texas, FoxNews.com has learned.

The exchange would involve Afridi and Dr. Aafia Siddiqui, a U.S.-trained neurosurgeon who left Massachusetts after 9/11 and resurfaced in Afghanistan where she was arrested for trying to kill U.S. soldiers. Siddiqui is currently serving a sentence of 86 years at a maximum security prison in Fort Worth, Texas. She has denied the charges and role with Al Qaeda.

A Pakistani Interior Ministry official who requested anonymity told FoxNews.com the prisoner exchange is still being drafted. The official said it would take at least a month before the newly formed task force constituted by Pakistan’s Interior Minister Chaudhry Nisar Ali Khan can finalize an agreement to present to the Obama administration and discuss the terms of a deal.

In the Sunday attack that led to the adjournment of Afridi's retrial, a pair of suicide bombers blew themselves up amid hundreds of worshippers at a historic church in northwestern Pakistan on Sunday, killing more than 80 people in the deadliest attack against the country's Christian minority. A wing of the Pakistani Taliban claimed responsibility.