A gay man who went through months of electric shock "therapy" in a university psychology department 50 years ago has demanded an apology.
Chris - not his real name - went to his GP for advice in the 1970s, when he became aware of his sexuality in his mid-20s.
The doctor said he knew someone who could "cure" him. He was referred to a clinical psychologist at the University of Birmingham.
Believing it would help, Chris underwent the painful and distressing sessions many times a week for several months.
This, he says, has led to more than 40 years of "extreme" post traumatic stress disorder and poor mental health.
'Hefty electric shock'
Homosexuality had only been de-criminalised in 1967, and mainstream society was still deeply disapproving of it in the 1970s.
Chris, now 74, remembers being told that "even having a sex change" would be better for him than continuing to live as a gay man, and so he committed to the prescribed treatment which he had been guaranteed would work.
Recalling the sessions, Chris said: "I would be sat in a room, with a projector screen and photographs to look through. An electrode was attached to my ankle and wrist.
"A photo of a man would pop up, and if you weren't quick enough to flick to the next picture, you would get a hefty electric shock. Then photos of women would pop up, with no consequence at all."
The idea of the treatment was to associate homosexual desire with pain and unpleasant feelings. After Chris had finished all of the sessions, the researchers encouraged him to start romantic relationships with women.
"I met Ruth [not her real name] on a blind date and explained everything to her. We went to see the people at the university together, and it didn't scare her off. We were told that I would be perfectly 'normal' on the other side of the treatment."
However, this was not the case. The treatment did not "cure him" or alter his sexuality. Nevertheless, the couple married, and are still together today. Chris says he couldn't have found a "better friend".
But 42 years on, they have still not consummated their marriage.
'Nowhere would even interview me'
Even though Chris was not detained, or forced to go through the treatment, he says he "lost everything" as a result of it.
Chris had a successful career as a teacher, until his school found out where he was going during his afternoons off.
"I was a school master, I taught art and I was a head of year. When I had to have two afternoons a week off to attend the 'therapy', I was not entirely honest with the school. I said I was being treated for depression."
He believes that one of the researchers "outed" him as gay to his school.
"My head teacher was a very religious man. I was definitely terminated because he thought I was gay. I was advised to leave teaching and I had to find an entirely new career, but nowhere would even interview me."
'Wall of silence'
Therapists and medical professionals have tried to support Chris over the years, but he stresses that nothing has completely alleviated his suffering.
Three years ago, Chris began looking for "closure".
He tracked down one of the post-graduate students who was working in the psychology department at the time of his "treatment". He provided Chris with evidence of the electric shock therapy.
"Even with undeniable proof, I was met with an absolute wall of silence by the university. They tried to deny that this ever happened," he said.
Correspondence seen by the BBC shows that the University of Birmingham did initially deny that Chris' electric shock therapy ever took place.
Staff claimed that they do not keep records for more than 25 years, and therefore they had "no record" of it. However, Chris persisted and their response changed.
"They eventually blamed the researcher, saying it was just his private project, and nothing to do with the university."
But Chris contends that all meetings took place in the University of Birmingham's department of psychology, with university staff, university students and university equipment.
"I don't want to sue the university into oblivion, I just want an apology for the years of pain they have put me through. I just want closure."
The University of Birmingham spokesman said: "While we are unable to find any evidence that this was a university sanctioned research project, we are aware that during the late 1960s and 1970s there may have been some isolated activity of this nature.
"We believe that this was wholly inappropriate and deeply regret that such potentially harmful activity may have taken place; we have engaged with the individual on a number of occasions to highlight our regret."
It added that as an institution it believed all conversion therapies are "unethical, degrading and potentially harmful" and that it was committed to promoting equality, diversity and fairness irrespective of sexual orientation or gender identity.
Banning conversion therapy
In 2018, the UK government announced that "gay conversion therapies" were to be banned, as part of a plan to improve the lives of gay and transgender people.
Campaigners are still waiting for action, even after the Prime Minister promised it again this summer.
The term "conversion therapy" refers to any form of treatment or psychotherapy which aims to change a person's sexual orientation, or to suppress a person's gender identity.
While some violent practices which may be classed as conversion therapy, such as "corrective rape", are already covered by existing criminal offences, many religious practices, such as "group prayer", are not.
Nancy Kelley, chief executive of LGBT rights charity Stonewall, said the government needs to "stop dragging its feet" and bring forward a ban.
"It's now been two-and-a-half years since the government promised to end conversion therapy against LGBT people" she added.
"All forms of so-called therapy that attempt to change a person's sexual orientation or gender identity are cruel, degrading and unethical.
"You cannot cure being LGBT, you cannot erase us from society. Major UK health organisations like the NHS, psychotherapy and counselling bodies have rightly condemned these practices."
Chris is also calling for the government to "fix this mess."
"In this country it is illegal to train a dog using electric shocks, but it is not illegal to use electric shocks on a gay man," he said.
"I have had over 40 years of pain, and an immensely frustrating life. Why has the government still not banned conversion therapy?"
If you experienced electric shock therapy, and you feel comfortable sharing your experiences with BBC News, please get in touch with Ben.