For Wakeel Khan, the worst aspect of the disappearance of his son Hameedullah was initially not knowing his fate.
Hameedullah disappeared from the tribal region of Waziristan bordering Afghanistan in a 2008 military operation. For a while, it seemed that he had fallen off the face of the earth.
“It was five, six months after my son went missing that I found out he was at Bagram [the main US base in Afghanistan],” a visibly upset Mr Khan – who served in the Pakistan Army for 15 years – told the BBC.
“The Red Cross helped us get in touch with him in jail, but for two years, he couldn’t even tell us why he’d been arrested.
“Even now, whenever I ask him about his living conditions, the line just gets disconnected.”
All this is a far cry from Mr Khan’s earlier wish for his son to become a doctor. But Mr Khan is not the only one whose dreams have been shattered.
Haroon Khan’s nephew has also ended up in Bagram prison.
Years in jail
“My nephew took his father to the doctor in Karachi and stepped out for a moment. A year later, the Red Cross told us he was in Bagram. We’ve never gone to see my nephew. He’s specifically asked us not to risk getting into trouble ourselves.”
“My crime has not been proven and they have no evidence against me” Saeed Akbar, Pakistani inmate of Pul-e-Charki
Wakeel’s son and Haroon’s nephew are among hundreds of people allegedly arrested from all over Pakistan and Afghanistan after the US launched its invasion of Afghanistan in 2001.
Some were subsequently found not guilty and set free – but only after they had spent years in jail.
The two men are among seven families who have lodged a case in a Lahore court seeking their early release.
The Pakistani government says that in addition to these cases, these there are 13 other confirmed cases of Pakistanis being held at Bagram.
Pakistan’s foreign ministry has confirmed their presence at Bagram but refuses to speculate on the date of their release.
“We hope they will be set free soon, but that decision has to be taken in Washington,” foreign ministry spokesman Abdul Basit said.
The precise number of Pakistanis in US detention in Afghanistan has until now remained a mystery.
“Our sources and officials say there are 25 Pakistanis at Bagram,” said Amana Masood Janjua, who leads a campaign in Pakistan for the release of missing people, including her husband.
A US spokesman at Bagram told the BBC that “a very small number – under 50 – of our detainee population are third-country nationals [neither US nor Afghan citizens] and that out of this group, slightly more than half are Pakistani”.
“The US captures and detains individuals – including, in some cases, individuals who are not Afghan nationals – consistent with the law of armed conflict,” the spokesman said.
It is estimated that there are at least 265 Pakistanis held in jails in Afghanistan “We ensure all detainees are treated humanely, in accordance with all applicable US law and policy, including (Common Article III of) the Geneva Conventions.”
Access to the Bagram detention centre is restricted, but the BBC Urdu Service’s correspondent Riffatullah Orakzai visited Pul-e-Charki jail on the outskirts of Kabul to see whether it holds Pakistani prisoners accused of having links to the Taliban or al-Qaeda.
He discovered that the jail held more than 100 Pakistanis and that a total of 265 are being held throughout the country.
“I was arrested four years ago from Chitral (a mountainous district in Khyber Pakhtoonkhwa province of Pakistan) for treating the Taliban,” said Saeed Akbar.
“My crime has not been proven and they have no evidence against me. Initially they said I was working for the intelligence agencies, then they said I’m a doctor.”
Mr Akbar was arrested while travelling from Chitral to Peshawar via Afghanistan’s Kunar province. Chitral’s road links are often severed from the rest of Pakistan during winter and this is the only overland route that it is possible to take.
Hafiz Muhammad Shoaib is another detainee, hailing from Pakistan’s Punjab province.
“The Pakistani government is involved in both their abduction and rendering, which is unconstitutional” Reprieve spokeswoman Sara Bilal
“I was arrested at the Torkham border four years ago, allegedly for spying for the Taliban. I’ve been taken to court twice but the courts here don’t listen to what the accused has to say – they just go by what’s in the records. So I’ve been convicted of spying, even though I’m innocent.”
Since Pul-e-Charki is a high-security prison, contact with the outside world is limited.
Human rights lawyers in Pakistan are increasingly resorting to the courts as a means of addressing these cases. But it is a battle with no clear sides.
For the most part, the exact charges against the prisoners and the supporting evidence supporting the allegations are vague and indistinct.
Equally unclear is how they were arrested and how they ended up in Afghanistan. Furthermore, there are questions as to whether these prisoners will be tried in courts at all.
All these concerns have resulted in lawyers questioning the conduct of the Pakistani state.
Sara Bilal represents the UK-based pressure group, Reprieve, and is pursuing the case on behalf of the seven Pakistani families at the Lahore court.
Her petition states that they were definitely picked up from Pakistan and that the intelligence agencies were involved.
“They couldn’t have been arrested or rendered without the agencies’ involvement and by that reasoning, the Pakistani government is involved in both their abduction and rendering, which is unconstitutional,” she says.
Wakeel Khan has suffered years of anguish over the fate of his son Pakistan has in the past admitted handing over several suspects to the US but despite several attempts by the BBC to contact him, the interior minister was not available to comment on Ms Bilal’s allegations.
The prisoners at Pul-e-Charki and Bagram are at least visible. Scores of other Pakistanis are still unaccounted for.
For example, little is known of the fate of hundreds of Pakistanis who followed religious leader Maulana Sufi Mohammad from Swat district to fight the Americans in Afghanistan in 2001.
Some of the lucky ones returned, but others did not. Even today, their whereabouts are still not clear.
Foreign Office spokesman Abdul Basit says that on this case – and no doubt on many others as well – they do not have any relevant figures.
The trauma of the prisoners and the affected families looks set to continue.