The brother of a British doctor who died in Syrian custody has praised him as a "courageous, principled man" who was "driven by his morals."
Dr Abbas Khan, 32, was on the verge of being released when his family were told of his death by what the Syrian government calls suicide and they say was political mturder.
Today his younger brother Shahnawaz Khan said he had "modelled his personality" on Abbas and called him an "inspiration" who was "driven to help others."
The touching tribute comes as the family revealed a letter in which the doctor expressed his optimism at being released, and his hopes of being home in time for Christmas.
The Evening Standard reported that the letter, dated December 7, stated: "To everyone! Good work guys, seems they are now responding to the threat of a foreign delegation. But keep up the pressure. We don't want to lose the Christmas period 'window'. Till I'm not released - I'm not free! They can release me immediately if they wanted to."
Tonight, their mother Fatima made an emotional plea to the Syrian authorities, who she blames for killing her son, to return his body.
Weeping, she told ITV News: "If you can't give me him alive, at least give me his dead body.
"I blame myself. Until I die. I blame myself."
Dr Abbas Khan was just days away from being released on the orders of President Assad when his family were told he had killed himself.
Shahnawaz said: "He was an introvert character, but he was dedicated to his job and his training, and driven by his morals. He believed in putting others first.
"We were aware of the fact that the Syrian refugees and the population at large had been abandoned, and he saw that he could take it upon himself.
"When you're faced with that sort of circumstance, with the skills you have, with the training you have as a doctor, you go into a certain degree of somaticity. You say: 'I've just got to do this, and I'm going to do it one way or another.'"
He said he "wasn't surprised" when his brother told him he was in Syria and at one point even planned to travel there with him, saying that "without a shadow of a doubt" he would have been captured too.
Shahnawaz went on: "My mother is beside herself - inconsolable. She really thought she was going to bring her son home, and she feels that maybe she didn't do enough. But she did more than I think any mother would do.
"We've had the heart and soul ripped out of our family, and it will take time for that to heal. I can't put into words the loss that we're feeling."
Dr Khan, an orthopaedic surgeon from London and avid motor racing fan, was captured in November 2012 in the ancient city of Aleppo after travelling from Turkey to help victims of hospital bombings.
Syrian state news claimed the government has given a medical report to the Czech Embassy, who are acting for the British government since the end of diplomatic relations last March, which proves the death was a suicide.
But f oreign Office minister Hugh Robertson said there was "no excuse" for Dr Khan's treatment and that Syrian authorities had "in effect murdered a British national who was in their country to help people injured during their civil war".
He also said the Government was seeking "urgent clarification" about Dr Khan's death, which was "at best extremely suspicious".
The family rejected as "complete fiction" claims by Syrian deputy foreign minister Faisal Mekdad that Dr Khan had used his pyjamas to take his own life, while Bradford West Respect MP George Galloway, who was due to bring him home from Damascus on Friday, said suicide was "impossible to believe."
Mr Mekdad told the BBC: "I don't think there is an intelligence in Syria who do not implement what they are instructed to do. Dr Khan was treated very well, very nicely."
More than 1,000 people are believed to have died in the custody of the Syrian security forces since the start of the crisis in the country in March 2011, according to Amnesty.
The middle brother in a f amily of three doctors, Dr Khan planned only a short stay and was just two days from flying home when he was arrested.
When his family heard of his disappearance, they waited at Heathrow airport, hoping he would be on his scheduled flight.
Staff at the hospital where he'd been treating victims of war said he had "gone to get some fresh air" and never returned, leaving his room untouched.
What followed, said Shahnawaz, was a "complete blackout" during which the family "entertained every option and lobbied at every door."
He said: "I can't go into how arduous and tumultuous a process it's been. Safe to say that I wouldn't wish it on my worst enemy, because mentally and physically it is the most physically draining thing that you can do."
The Khans eventually got word through the Indian embassy that a doctor "very similar" to Abbas was being detained.
Only their mother Fatima was granted a visa, and when she found him he weighed less than five stone and could barely walk.
In the months afterwards she brought chocolates and letters while he had begun requesting books to read.
Shahnawaz, who says he "grew up in the shadow" of his older brother and was trained at the same university, said: "He was displaying a great deal of fortitude, and he was in high spirits.
"We had a letter from him last week saying 'don't worry about me now, in this prison things are much better, my weight's picked up, I'm talking to Mum, there's a shop here, there's a gym, I'm working out.'
"That a man three days from release, from coming back to his country and to the soil that he was born on, would take his life after 13 months in detention in the most atrocious circumstances, is unbelievable.
"His children are very young, so they don't understand. They appreciate something's up. His wife Hanna is just devastated.
"He was the sole provider to them, so we'll all have to band together and find a way."
Dr Abbas leaves behind his wife Hanna, 30, son Abdullah, six, and daughter, Rurayya, seven.
Shahnawaz also blamed the British Government for not doing enough to bring his brother home.
He said: "We contacted the foreign office within 24 hours of him going missing. And the reiterated the same thing: 'we advised against travel to Syria, we have no consular services, and there's very little if anything we can do for you.'
"We thought surely the Syrians would relent if the highest officials were willing to just take five minutes of their time to push the case. No one was willing to do that.
"We pressed them at every turn that there was a risk to life here, and that fell on deaf ears. "
The Foreign Office said it "consistently sought consular access to Dr Khan and information on his detention" and "raised his case with the Syrian Regime".
Dr Khan's family criticised their MP, Chuka Umunna, for failing to join a delegation to Syria to lobby for the surgeon's release.
Shahnawaz Khan told HuffPost UK: "My sister had arranged a delegation of lords, including Lord Ahmed, to visit Syria when my brother would be freed, and she had rung him, asking him to go.
"But a member of his office said he would not go because "he doesn't want his mother in the same situation as Abbas' mother". And he was even advising many others not to go."
A spokesman for the Streatham MP said the Shadow Business Secretary had been acting on the advice of the Foreign Office.
He said: "Mr Umunna has been in contact with and met several members of the family over the last 12 months, trying to do what he can to assist the family as they tried to secure Dr Khan's release.
"The advice of the Foreign Office and others has been not to travel to Syria on safety grounds. In light of this, Mr Umunna did not feel it would be fair on his own family to put himself at risk and travel to Syria in these circumstances. He has always been clear that whether other Parliamentarians choose to travel to Syria is a matter for them."