Warning: This story contains content that readers may find distressing

Media playback is unsupported on your device Media caption "It was as if I was going to be impressed by how vulgar it was"

"Rape the whole flat to teach them a lesson," one message read.

"Oh god. I would hate to be in the firing line if I had a vagina," said another.

Anna - not her real name - was scrolling through hundreds of sexually violent messages on a Facebook group chat.

To her horror, she and her female university friends were mentioned dozens of times.

The men writing the messages were - like Anna - studying humanities at Warwick University.

But they weren't just her coursemates. They were her close friends.

In the weeks that followed Anna's discovery of the chat, word spread across campus. What begun as a private "lads' chat" quickly escalated.

Anna and a female friend - one of those also targeted in the chat - complained to the university.

After an internal investigation, one student was expelled and given a lifetime campus ban, two were given 10-year bans and also expelled, and two more were excluded for a year.

But after two of the men had their 10-year bans reduced to 12 months, serious questions were raised about the university’s handling of its investigation.

A year on, the university is still raw from the fall-out with many students and academics asking: what went so wrong at Warwick?

Watch the documentary

The Warwick Uni Rape Chat Scandal is available on BBC iPlayer

'Lads' chat'

Early last year, Anna, then 19, was sitting on the sofa in her student house when a stream of explicit messages began popping up on her friend's laptop.

As more came through, she asked him what they were about, and he laughed.

"He said: 'Well, if you think that's bad you might want to see our lads' chat'," Anna says. "That's when he took me through a year and a half's worth of rape threats."

As she sat there, she saw in the Facebook chat that he and his friends had changed their names to those of notorious serial killers and serial rapists.

"They were talking about a fellow student. They were talking about abducting her, chaining her to the bed, making her urinate on herself, and then sleep in it."

Much of the content was even more graphic.

"This wasn't just a flippant comment," Anna says. "This was an entire online community... they were proud that it was horrific."

She searched the chat for references of her own name. It came up hundreds of times.

At first, Anna says her male friend dismissed the chat's contents as "how boys talk", saying it was a joke.

She continued scrolling, taking screenshots as she went.

"I just told him that it was for my own peace of mind," Anna says. "He could see me getting more upset and more upset. And I think that's when it started to dawn on him that this was probably a lot more serious than he thought it was."

Soon, he took a different tone, suggesting he'd known the contents were unacceptable and that he'd shown it to her to protect her.

But as she flicked back through reams of messages about gang rape and genital mutilation, her instincts told her otherwise.

"I didn't know what to do because these people [in the chat] were a huge part of my life," she says.

A few days later she went back to her parents' house for the Easter break. But the prospect of returning to face the men again gave her panic attacks.

"I was getting my stuff ready to go back and I couldn't go through the door," she says.

It was then she decided to complain to the university.

'Potential for conflict'

After Anna and one other friend who was repeatedly targeted in the chat submitted their complaint to the university, they were told they would be formally interviewed.

But one thing stuck out: the man who would be interviewing them was the university's director of press.

"I thought straight away it was a very strange appointment for an investigating officer," Anna says.

As head of the press office, Peter Dunn was responsible for dealing with the media and protecting Warwick's reputation as one of the top universities in the UK.

As investigating officer, he was responsible for examining misconduct allegations and recommending which punishments - if any - the men should face.

Mr Dunn held both of these roles, despite the case gaining national media attention after it was reported by the student paper The Boar.

In February 2019, the university admitted "the potential for conflict" between Mr Dunn's two roles, but insisted relevant press duties were "delegated" during the investigation.

Media playback is unsupported on your device Media caption The women mentioned in the chat explain how the 'lads chat' spread

However, in one email seen by the BBC, Mr Dunn told the women he was planning to release a statement to the media about their case during the investigation, and asked for their feedback.

"It just felt really violating," Anna says. "This person that's writing press statements knows such intimate details about my life. It was a very surreal experience."

The university told the BBC: "We appreciate there are legitimate questions raised about the university's handling of this extremely delicate case. We continue to support the investigating officer for this case, Peter Dunn."

A month after the women were interviewed, five of the men involved in the chat were banned from the university. Two were banned for 10 years, two were banned for one year, and one was given a lifetime campus ban.

Anna and her friend said they were not kept informed of the outcome and instead found out in the press, meaning they didn't know which punishments corresponded to which men.

But her case wasn't closed - the two men who had been banned for 10 years appealed against the decision.

#ShameOnYouWarwick

After a four-month wait - which the university put down in part to a staff member taking a late summer holiday - they had their bans reduced from 10 years to just one.

"I was never given an explanation. We were told new evidence had come to light but I don't know what the new evidence is," says Anna. "I was starting to feel like I was going to have to finally drop this... I felt like it was just me and my other complainant against an entire institution that was never ever going to listen to us."

Anna and her friend made one last attempt to outline their concerns about the investigation to the university.

But vice chancellor Prof Stuart Croft wrote to them saying he found "no evidence of procedural irregularity or bias" and declared the investigation closed.

Three weeks later, one female student connected to the case went on Twitter and soon #ShameOnYouWarwick started trending.

The story was once again the subject of intense media scrutiny. Academic departments began publicly distancing themselves from the university management.

Soon after, Prof Croft released a 1,000-word statement in which he spoke extensively about his reaction to reading the chat, saying it "produced a feeling of utter revulsion".

But his comments were regarded as tone deaf by the student community.

Three days later, he announced the men who had had their punishments reduced would not return to the university. It is not clear whether it was the university or the men who had made this decision.

But this did not stem the feelings of anger on campus: two days later hundreds of students and academic staff marched on the offices of senior management.

On the morning of the protest the university released a statement to the press saying they were "deeply sorry" for the distress caused to the victims.

The women involved never received a personal apology from the university.

Never want to go again

The case at Warwick has raised questions about how universities deal with serious sexual misconduct and problems arising in online chat groups.

The university has since launched a review into its disciplinary and appeals processes, which is due to conclude in summer 2019.

Prof Croft told the BBC he hoped the review would "demonstrate our learnings and help our community to better live our values".

But there has been no sense of closure for the women involved. Anna, now in her third year, is revising for her final university exam on Friday.

"The university caused so much pain and so much damage and this is carrying on over a year later," she says.

"The trauma of feeling strong enough to come forward and being punished for that by the university is probably the most damaging part of this.

"I don't want to go to my graduation. I just can't wait to never have to go to Warwick ever again."

Update: The university released a statement on Tuesday in response to the BBC's story, saying it "apologised for any part we played in causing distress to members of our community", and adding that it was making changes "which minimise the chances of these mistakes being repeated".

The Warwick Uni Rape Chat Scandal is available on BBC iPlayer