Asia Bibi, who was moved to a safe house in Karachi after her acquittal was upheld by the country's Supreme Court last month, is reportedly experiencing very low blood pressure.
A source told the Daily Mail: "Everyone is very worried. She won her appeal and was supposed to be out of Pakistan by now.
"Even though the government says she can leave, the army has all the power in this case".
It has been claimed officials fear Ms Bibi will cast a negative light on Pakistan if she gives media interviews about her lengthy court case and spell in jail.
But authorities have insisted the mother-of-five is a free woman and has been living under guard for her own protection.
Behind the scenes, foreign diplomats have been trying to pave the way for her departure from Pakistan.
It is believed Ms Bibi may intend to travel to Canada - where members of her family have already been offered asylum.
Ms Bibi was accused of insulting the Islamic prophet Mohammad after a row involving a group of Muslim women over the use of a water cup. She always denied any wrongdoing.
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