In their first ever interview, the teenage sons of Shaker Aamer told Sky News of how their hopes of a reunion have been raised and then dashed.
Mr Aamer has been detained without trial inside the maximum security prison for 13 years – even though he was cleared for release in 2008.
The British government has lobbied on his behalf, and his case has attracted cross-party support, but there has been no explanation as to why he has not yet been freed.
Although he was born in Saudi, his wife and four children are British citizens. They barely remember their father; indeed his youngest son, Faris, was born on the same day as Mr Aamer arrived at Guantanamo on Valentine’s Day 2002.
Faris celebrates his 13th birthday on Saturday and told Sky News “It’s upsetting and quite shocking that I’ve never met him in my entire life.”
His 15-year-old brother Micheal spoke of how their hopes have been dashed.
“We felt very happy,” he said.
“We thought there might be a chance for him to come home, but it just kept getting delayed.
“We just felt more sad because nothing happened. We’ve seen other people with their parents … seen how they enjoy themselves, how they’re so close to them.
“It’s like there is a part of our heart that is missing because we’ve been yearning for him to come home for many years and nothing’s happened yet.”
Mr Aamer took his young family and pregnant wife to Afghanistan in 2001. He says he was working for a humanitarian charity.
But a few weeks later the 9/11 attacks put the country at the centre of the US’ so-called ‘War on Terror’.
His family escaped to Pakistan but Mr Aamer says he gave himself up to the Northern Alliance and was then handed over to US forces.
The Pentagon compiled a lengthy list of allegations claiming he had ties to Al Qaeda.
His lawyer insists the allegations are false and are the result of torture or false confessions to earn rewards.
His supporters also stress that if the Americans actually believed them, they would not have cleared him for release.
Guantanamo spokesman Lt Col Myles Caggins told Sky News: “In 2009 Shaker Aamer’s detention status was reviewed. As a result he was placed in a category we call ‘eligible for transfer’.
“At some point in the future we will find a new home for him to be repatriated or resettled to.”
But Micheal was unimpressed when he saw the video.
“I feel very sad because the man said they were going to try to find him a home,” he said.
“But his home is here in London with his family.”
There have been various theories about the delay.
Some say the US may prefer to see him sent to Saudi Arabia, where he is less likely to speak publicly about allegations of torture. There is also the issue of compensation.
According to Lt Col Caggins: “We make these moves after a rigorous inter-agency process between our security officials, law enforcement and intelligence officials to ensure that transfer will be to a place that can maintain security assurances and human rights protections for those former Guantanamo detainees.”
Mr Aamer’s lawyer, Clive Stafford Smith, scoffs at that.
“The most obvious person in the entire world to release is Shaker Aamer because he would be coming to the country with the best record of released prisoners, Britain,” he said.
“And he would be coming to a place where we know his human rights are going to be respected, and he’s been cleared for eight years, and he’s got a wife and four children. What on earth is the argument against it?”
At least in recent years the family have been able to speak to their father. The International Red Cross has organised Skype video calls. Micheal remembers the first.
“We were all very excited,” he said.
“We were very energetic. We couldn’t wait to see him. And then when the call finally happened, we couldn’t believe it was actually him.
“His voice. We hadn’t heard it for such a long time.
“It was very surprising to hear his voice again. It was a shock. Skype has been very good at lifting our hopes up again because we’ve been able to speak to him, see how he’s doing, and he’s a very funny person.
“He always makes jokes. He lightens the mood a lot of the time. We talk about what’s going on in our lives, how our education is.”
Mr Aamer’s wife and daughter preferred to stay in the background and not be interviewed. Because both boys are under sixteen, we agreed not to show their faces.