Shaker Aamer was the last British resident of Guantanamo Bay. Here, he describes what it was like to be held without trial for nearly 14 years.

Aamer, 48, was held over extremely serious claims - that he had led a Taliban unit and was an associate of Osama Bin Laden. The US military classified him as a threat, but he was never charged.

His lawyers say the case against him came from unreliable allegations extracted during torture and that his treatment at the US military base in Cuba raises serious questions about the legality and morality of the so-called war on terror.

In an interview with the BBC's Victoria Derbyshire, Aamer tells his side of the story.

Image caption 1) WHY DID HE GO TO AFGHANISTAN?

The Saudi national lived in London for five years, settling with a British wife - but says he found it hard to be a practising Muslim in the UK.

"The way my wife appeared, wearing a full niqab, the way I am wearing a turban on my head, wearing an Islamic dress.

"Because people talk and say rubbish things about you, about your wife. Eyes chasing you everywhere you go.

"I want to be with people like I feel like I belong to. I want to feel like I'm normal, just like everybody else is doing the same thing."

Aamer denies he was an associate of terrorism suspects 20 years ago - but freely admits having attending talks in London given by Abu Qatada, a radical preacher who, as years went by, became increasingly extreme.

"I used to sit and listen to his speeches. And I know he's not a bad guy, that's exactly what I know [from the time]. According to my own knowledge he got nothing to do with bin Laden and he never, he never preached about him in his circles. And he never encouraged anybody to go to Afghanistan."

After Aamer rejected a return to Saudi Arabia, as his wife would have not been allowed to join him, they moved to Kabul.

"Under the Taliban at that time, it wasn't that horrible."

Image copyright Getty Images

He claims he was voluntarily doing charity work - helping to open schools for girls and proving wells.

"It wasn't an official charity as documented. No, it was our own way of helping that society. By doing our own things that we know we are good at. Especially, when we know that they need these things. And when you know how much it costs just to open a school, it's nothing. It's very little."

Commentary by BBC home affairs correspondent Dominic Casciani: "The late 1990s was a hugely important time in the development of modern Islamist political identity. During the Bosnian War, many young Muslim men fought to protect civilians from near genocide - this in their mind was a legitimate 'jihad' of self-defence - a just-war. For his part, Shaker Aamer says he went to Bosnia to do humanitarian relief work.

"Some Muslims debated whether they would be better off in an Islamic State - and for many the mysterious new state formed by the Taliban was worth investigating. So many went to Afghanistan with innocent charitable intentions. But at the same time, Osama bin Laden was also there, targeting and recruiting some for his extremist cause. Back in the UK, preachers like Abu Hamza, now jailed for life in the USA, and Abu Qatada, deported to Jordan, increasingly took hardline pro-al-Qaeda positions. As this debate raged, MI5 penetrated their circles and, to this day, intelligence chiefs regard these two men as among the most dangerous radicalisers the UK has ever seen."

Image caption 2) BAGRAM AND KANDAHAR

Soon after the 9/11 attacks on America, Aamer was detained in Afghanistan by bounty hunters tracking down and handing over possible al-Qaeda suspects.

He was first held by US forces at Bagram air force base near Kabul. He says a British intelligence officer was in the room when his head was slammed into a wall.

Media playback is unsupported on your device Media caption Aamer describes how he felt looking at pictures of the 9/11 attacks during his detention

"I have no doubt he is an Englishman, because the way he spoke, the way he is very careful, the way he was sitting far away, looking at me."

Aamer says he knows what happened to Ibn al-Shaykh al-Libi - the Libyan who erroneously thought that al-Qaeda had links with Saddam Hussein and confessed, allegedly under torture, they were linked together. Is it true he saw him taken out of Bagram alive in a coffin?

"Yes, it is correct."

Image copyright Getty Images

He was then taken to Kandahar air field where the treatment got "a lot worse", with US soldiers "given the right to do anything they want".

"They have something called 'welcoming party'. Where they really beat you up so that while you are still on the concrete, on the airport, before even they move you to check you and process your case. They did it for two, three hours and truly, truly, that's one of the times where I felt like I'm not going to live that night."

He says he was forced to stay awake for nine days, denied food, doused in freezing water and made to stand on concrete in the winter for 16 hours a day. One interrogator threatened to sexually assault his then-five-year-old daughter, he says.

"That was the hardest thing, the hardest thing that I ever hear. If you don't start talking, we will rape your daughter and you will hear her crying 'daddy, daddy'. That was completely inhumane. It was worse than the beating as well, worse than everything, just thinking of my daughter and I just sat there silent completely."

Image copyright Getty Images

Should Tony Blair, the then-prime minister, be held to account for what happened?

"The only thing I really would like to happen is for Tony Blair and for whoever in the government at that time is to tell the truth, just like I'm telling the truth to the world. The only goal I have at this time is to stop what is happening, which is still happening, which is Guantanamo.

"They know, all of them, they know what they were doing. Because I mean, if these guys are the head of the state, they don't know, who's supposed to know?"

Dominic Casciani: "A government spokesman says the UK stands 'firmly against' abuse, adding: 'We do not participate in, solicit, encourage or condone the use of torture or cruel, inhumane or degrading treatment or punishment for any purpose.' The problem is, nobody knows if, in the wake of 9/11, some UK officials did collude in such behaviour.

"Three years ago the government scrapped a semi-secret inquiry into claims of UK complicity in rendition - and its successor investigation is only just starting its work. The rules governing what UK intelligence officials should do if they suspect abuse overseas were only fully revealed in 2010."

Image caption 3) US CLAIMS AGAINST HIM

The United States government believed Aamer to be a military-trained al-Qaeda operative who recruited for extremist causes and had close ties to Osama bin Laden.

"Let's say all these allegations is true. Let's say that America, they were telling the world the truth about me. How come they cleared me? How come after six years I was in there, yet the George Bush government cleared me?

"I'm telling you right now, it's not true, all of them [the allegations] is not true. It's just a basic answer, it's not true. None of the allegations is true they've been saying about me."

Dominic Casciani: "MI5 investigated Shaker Aamer in the late 1990s. Today, he is not under criminal investigation - and in fact Scotland Yard offered to investigate the abuse he has since reported suffering.

"A spokesman for the US Department of Defense says it does not tolerate abuse. 'Shaker Aamer was lawfully detained at the detention facility at Guantanamo Bay,' he said.

"'He was transferred to the United Kingdom following a determination by the Secretary of Defense, consistent with statutory requirements, that security arrangements are in place to substantially mitigate Aamer's potential threat to the United States.

"'All Guantanamo detainee cases are different and there were a number of factors in this case that required further deliberation and coordination with our partners in the British Government.'"

Image caption 4) GUANTANAMO

On Valentine's Day 2002, Aamer was transferred to Guantanamo Bay where he says he was tortured.

"In the first few days, I knew this is a lot worse than what I expected. Because they told us we were going to be treated good. They told us that in Guantanamo you're going to have Geneva Convention, things like that. So we thought, OK, we're going to be dealt with as human beings. Nobody can do anything wrong to you because now you are in an American facility.

"But I was shocked. The first day I was shocked - not the first day, the first second I arrived - because they don't even allow you to walk. They drag you on your feet, they just drag you, pulling you. And then they start hitting you, left and right."

He says the best way he can describe Guantanamo is comparing it to a location in the Harry Potter books.

"They've got an island in Harry Potter, it says Azkaban. Where there's no happiness, they just suck all your feelings out of you. And, you don't have no feelings any more. And truly that's how I felt all the time. This is Azkaban. This is not from this world, because that's what they tried."

Aamer says he was subjected to a form of "cell extraction", which involved the use of violence against "non-compliant" prisoners, more than 300 times a year. But he says the torture was done differently.

Image copyright Getty Images

"In Guantanamo they were more careful. It's more discreet. It's more all the method of the torture in Guantanamo is totally like a cover up for it."

He says he was kept under solitary confinement in his cell for two years and 10 months.

"I end up making friends with all kind of creatures. One of them is the ants. Because they were beautiful, the way they were doing things and all that. I never knew that how much time I can spend with them. But I start watching them. I start learning the different ants, the different colours, the different way of doing things. And it was beautiful because I learn so much."

He says one incident of torture happened when they tried to get his fingerprints and photograph.

"They start beating my leg. They start, you know, pinching me. They start sticking their fingers in my eyes. All the pressure points and all that. And I'm screaming, screaming and screaming. And they said give us the picture. Give us the fingerprints. Give us the written scan. And then they brought a big Maglite for two-and-a-half hours non-stop. I have something called floaters now, maybe because of it.

"Did they break my spirit? I can assure you, no. But did I get tired? Did I get sick of what I'm doing? Did I feel like I need to stop? Yes."

Aamer says they also used to use white noise and loud music, which he didn't mind: "I just used to sing with it." Here I Go Again by rock band Whitesnake provided particular consolation.

Image copyright Department of Defense

"I used to [sing it a lot], because the words, I thought the words fits me. The words makes me feel like, yeah, it's me again. [It goes] "Like a drifter I was born to walk alone, 'cause I know what it means to walk alone the lonely street of dreams." And it's true because it's just dreams. Dreams that I would be home one day, dreams that I would be free, dreams that Guantanamo would be closed."

Aamer says he does not plan to pursue legal action against the British government, but he "cannot talk" about compensation.

"I do not want to prosecute anybody. I just want people to tell the truth. So we can really understand what happened and stop it from happening again."

He says he always believed he would be freed - and he will continue to campaign to close the prison camp.

"I had no doubt from day one. I will be out because I have no doubt that I did not do anything wrong to deserve what happened. And I know, justice will prevail. Years, after years, after years. Justice will prevail. It took 27 years with Nelson Mandela to get out and to be the president of his country. It took me only 14 years to prove to the world that I am the good person and they are the bad people.

"I need you to please let me tell the world the truth about Guantanamo. Let them know exactly what's happening because the world has the right to understand what's happening at this time. I will do my best to close that place. And I'm willing to go to Guantanamo back again. If they need me to go back to help them to close that place, by Allah, I will go back."

Dominic Casciani: "Whatever the alleged intelligence case for investigating people who were swept up in Afghanistan during the aftermath of 9/11, one of the legacies of Guantanamo Bay is that it has been used by extremists for their own ends. When the self-styled Islamic State group dresses hostages in orange jumpsuits before killing them, it is a very deliberate reference to the facility and what modern-day jihadists claim the West does to the Muslims. Shaker Aamer has denounced these extremists - and that may be a very powerful moment in attempts to undermine them."

Shaker Aamer: Extremists 'have no right to live in the UK'

Image caption 5) COMING HOME

Shaker Aamer flew back to the UK on 30 October after almost 14 years in detention. He says he did not know he was going to be released until an hour before he left. When he landed at Biggin Hill airport in London he underwent medical tests and met his wife.

"It's hard to know what to feel. I mean, it's something we used to dream about, something we used to fight for and all that. When it happened, it's like really, did it happen? Am I really home? You got all this mixed feeling of crying, laughing."

Aamer says his first words to his wife were "I'm back" and they both cried. His four children are now teenagers. He had never seen his youngest son who was born the day he was transferred to Guantanamo.

"I'm a father who did not practise his fatherhood for 14 years. I left them when they were little tiny kids, hugging them, carrying them all the time. And now they are grown up.

Image copyright PA

"Even though it was a happy moment, it was sad in the same time. Because it was happy that I've seen my kids again, but it was so sad that the feeling is not that they are my kids. They look at me and they're just trying to know who is this person? But through their eyes, I feel like they are just looking at a stranger.

"Even though it's been a month and a little bit more [since returning to the UK], things change a little bit, and they start to realise that their dad loves them so much, and he's trying to do everything to comfort them, to be there for them. And they are coming along, little by little."

Media playback is unsupported on your device Media caption Aamer describes what it was like to see his children again

The best thing about his release is "freedom itself", he says.

"Just to feel that you are free. Just to wake up and know that nobody's going to tell you what to do and how to do it or just to wake up without knowing that you're going to be shackled in every step that you take out of that cell."

The Victoria Derbyshire programme is broadcast on weekdays between 09:15 and 11:00 on BBC Two and the BBC News channel. Follow the programme on Facebook and Twitter, and find all our content online.

Chapter heading photos courtesy of Getty Images and iStock

Subscribe to the BBC News Magazine's email newsletter to get articles sent to your inbox.