The British academic jailed for spying in the United Arab Emirates (UAE) has told how he endured “psychological torture”.
Matthew Hedges, 31, said he was forced by the Emirati authorities to stand “all day” in ankle cuffs.
Mr Hedges said he suffered panic attacks and had suicidal thoughts.
He told the BBC he was asked to act as a double agent in the UK’s Foreign Office, and confessed to being a captain in MI6 to stop the “torture”.
Mr Hedges had denied spying and said he had been researching his PhD, but was jailed for life last month after a five-minute trial.
The UAE government said the Durham academic was “100% a spy”, but pardoned him on 26 November.
Speaking to John Humphrys on the Today programme on Radio 4, Mr Hedges said being in a cell was “was lonely and isolating”.
He said he was given a “cocktail” of medication to treat his depression and anxiety.
He said: “There was no natural light – I wasn’t allowed to do anything to distract myself. My mental health was deteriorating.
“I was handcuffed and blindfolded. I had to stand all day in ankle cuffs.”
He said he was accompanied by four guards just to go to the bathroom.
Mr Hedges said standing in ankle cuffs was “mentally exhausting”, but that adrenaline would kick in and help him cope.
He said shortly before his arrest he was due to have counselling to deal with anxiety and depression.
He said: “I could not manage my thoughts throughout the incarceration.”
He also said he regularly had panic attacks and some nights he dreamt of hanging himself in his cell.
He said he was only able to speak to his wife Daniela Tejada – who had been campaigning for his release – once a week.
During hours of interrogations he said the psychological pressure was so great he confessed.
“I panicked and told them I was a captain in MI6 – I told them what they wanted to hear.”
He also spoke of how he felt when he was sentenced to life in prison.
“It was total shock – I wasn’t able to process it. I couldn’t say goodbye to Danni.”
Ms Tejada said academics would now have to think twice before doing research in the UAE.
She said: “At the heart of it it’s about drawing red lines. I think the biggest issue is naturally the fact that there is no academic freedom in the UAE but also the fact that the red lines aren’t clearly drawn.
“So it’s sort of every man on their own. Each academic will have a different experience – to assess how safe it is to do research.”