The U.S. raiding party took bin Laden's body from the hideout in Abbottabad but left behind Amal al-Sadah and her children, as well as two other wives and four other children, who Zakaria Ahmad al-Sadah said were bin Laden's grandchildren.
Sadah said that his sister, her children, and the other wives and children were being kept under de facto house arrest in a small Islamabad apartment that was sparsely furnished and had little or no natural light. He said Pakistani security personnel guarded the apartment. He declined to disclose its precise location.
He said the children were so traumatized that "I had to teach them how to smile."
His sister, now 31, married bin Laden around the year 2000. Their oldest child, Safiya, about 12, reportedly was cradling her wounded mother when Pakistani officials reached the compound in Abbottabad just after U.S. forces had left.
"These are innocent children, totally innocent. These are becoming psycho," Sadah said. "Their psychological problems are getting worse and worse."
"For the last nine months, they have not seen the sun. They are just being kept alive."
The two other bin Laden wives held in the apartment are Khairiah, about 62, and Siham, about 54, both Saudis who had also lived in Abbottabad with him, along with four of his grandchildren.
The U.S. raid on the bin Laden compound killed one adult son, Khalid, who was Siham's oldest child, aged about 22. The bin Laden grandchildren are likely to be Khalid's offspring.
The official Pakistani commission that formed to investigate bin Laden's presence in the country interviewed his wives and called in October for them to be sent back to their home countries.
Sadah said the repatriation awaited only the signature of Interior Minister Rehman Malik. However, it's likely that the ISI, the nation's leading spy agency, is holding the family members and that the decision on their release isn't in the hands of the interior minister, who did not return calls seeking comment Tuesday.
There's no evidence that any of the wives of bin Laden, who married six times and fathered at least 21 children, were involved in al-Qaeda. Sadah said his sister was a "housewife" who spent her married life only raising their children.