Warning: contains details of alleged sexual offences and misconduct
Two women have told the BBC they were raped during the filming of one of Channel 4's biggest shows, Married at First Sight UK, while a third has described an allegation of a non-consensual sex act.
The show did not do enough to protect them, they all said.
Channel 4 was aware of some allegations before broadcast, and all the episodes featuring the women had been available on its streaming service.
On Monday afternoon, Channel 4 said it had removed all episodes from streaming and linear services, alongside MAFS UK social channels.
Reacting to our findings, the chairwoman of a new creative industry watchdog described Married at First Sight UK's format as one with "high levels of risk" which are "certainly not being managed properly".
Channel 4 had previously told Panorama that all the allegations were wholly uncorroborated and disputed.
When approached by the BBC on Monday, Channel 4's outgoing chief content officer, Ian Katz, said he had not seen the Panorama documentary, adding: "They are obviously very serious allegations. We want to see the show and when we see the show we will respond."
In a statement released shortly after BBC News published this story, Channel 4 said it had commissioned an external review last month of welfare on the show "after being presented with serious allegations of wrongdoing".
Lawyers for CPL, an independent production company which makes the UK version of the show, said its welfare system was "gold standard" and industry-leading, and that it acted appropriately in all these cases.
A Department for Digital, Culture, Media and Sport spokesperson told the BBC that the allegations were "serious", and that "everyone working and participating in television must be treated with dignity and respect at all times".
The spokesperson continued: "All allegations must be referred to the appropriate authorities and investigated with the full co-operation of those involved, with action taken to ensure that the highest standards are upheld and there are consequences for criminality or wrongdoing."
An Ofcom spokesperson said: "Under our rules, broadcasters are required to take due care over the welfare of people who might be at risk of significant harm as a result of taking part in a programme."
"We note that Channel 4 has launched an external review into contributor care on MAFS UK and we await its findings," they added. "We will review this and all other evidence made available to us."
Billed as a "bold social experiment", Married at First Sight UK - known to many as "MAFS" - sees single people agree to "marry" total strangers, after meeting for the first time at their mock weddings.
The marriages are not legally binding, but viewers see the couples go on "honeymoon", before moving in together and navigating their relationships - all while being filmed, almost every day.
The three women we have spoken to are all making allegations about the men they were partnered with and said that they are speaking to the BBC because they feel they should have been better protected. One said she wants CPL to stop "allowing harm to come to people".
Married at First Sight is a highly successful global TV franchise. Many couples say they enter the show with the aim of finding love. Others are seeking social media fame.
The UK version, which has been running for 10 seasons, is broadcast at prime time on Channel 4's sister channel E4. All episodes had been available on the streaming service All4.
Audience figures often top three million, making the show one of the jewels in Channel 4's crown.
The latest season has already been filmed and is expected to air this year.
"I don't think that because you're going on reality TV, you deserve in any way for things like this to happen to you," said Shona Manderson, the only woman of the three who is identified.
On screen, the couples talk to relationship experts about how the "marriages" are working. Away from the cameras, like many TV productions, CPL said it vets contributors before casting, carries out psychological checks, and provides oversight by a trained welfare team and access to psychologists and ongoing support.
The allegations uncovered by Panorama are "disturbing" and "incredibly worrying", said one of the country's leading women's safety charities.
"The tragic reality is that violence against women and girls does not discriminate and can impact anyone, even if they are being watched by millions on national television," said Women's Aid.
One of the women, whom we are calling Lizzie because she wants to remain anonymous, said she noticed "red flags" about her partner on the show almost immediately. We are also withholding some details to protect her identity. Anyone who makes an allegation of rape is entitled to anonymity by law.
During the "honeymoon", Lizzie said her onscreen husband often lost his temper in private.
"He would just explode, he would go into this absolute focused anger," she said.
Off camera, Lizzie said he told her that he and his ex-partner had been "violent" towards each other. Feeling worried, Lizzie told CPL's welfare team.
Lawyers for CPL told us that when welfare spoke to her onscreen husband, he told them he had been the victim of violence, not the perpetrator.
They said CPL discussed this with Lizzie, who told them she did not feel at risk.
By then, Lizzie had already started sleeping with her onscreen husband, but she said the sex soon turned violent. He would bruise her during sex, she said, even though she "kept saying stop".
Lizzie said at first she was too scared to tell anyone. "He said that if I told anybody what had happened, that he would get someone to throw acid at me," she said.
She said that, while they were alone, she tried to speak to him about "bringing everything up" with the onscreen experts but he "threw a temper tantrum and threatened to leave".
That night, she said, he attacked her.
"We were in our apartment, on the sofa, and he tried to have sex with me. And I kept saying no, that I didn't want to do it.
"But he kept saying, 'You can't say no, you're my wife'. And he just did it anyway."
Lizzie described what happened as "penetrative sex" and said she had "fingerprints from where he'd grabbed me and forced me".
"I just completely froze with fear and I never, ever thought anything could scare me that much," she recalled. She said the next morning, as soon as her onscreen husband had left the apartment, she messaged the welfare team.
She said she showed them her bruises and told them everything, aside from the alleged attack itself.
One welfare team member took photos of the bruises, which Panorama has seen.
Lawyers for CPL said the bruises were described to the welfare team by Lizzie as being the result of rough, but consensual, sex.
They said Lizzie did not tell CPL about her partner having told her that she "can't say no" to him, and that the acid-throwing remark had been reported as a passing comment, not a threat.
CPL acted immediately once Lizzie said she felt unsafe, the lawyers added.
Lizzie said she still took part in filming because she got "so wrapped up" in being on the show, "that I kind of lost what reality was actually like." But months later, when the show aired, she said she took "a total nosedive" with everything.
Before the series finished airing, Lizzie messaged a welfare producer, in which she said she had been sexually assaulted.
CPL's lawyers have told Panorama that CPL followed this up with Lizzie and took it to be a reference to the rough but consensual sex previously reported to them.
After the show went out, Lizzie spoke to the MAFS UK psychiatrist and told him she had been raped.
Lawyers for Lizzie's onscreen husband said he denies rape and said that all sexual contact was entirely consensual. He also denies being violent towards her or making violent threats to her, they said.
Lizzie now wants to pursue a legal claim against CPL.
The show demonstrated "a lack of curiosity, a lack of the ability to ask important questions and the failure to implement basic safeguarding measures," Lizzie's barrister Charlotte Proudman has told Panorama.
Channel 4 said it was only made aware of the rape allegation after the series had been broadcast, and it would be wrong to assess contemporaneous welfare and editorial decision-making by Channel 4 and CPL based on knowledge they did not have at the time.
Lizzie's episodes had remained available to stream on All4, as had those featuring another woman, whom we are calling Chloe to protect her identity. We are also not revealing some details.
Chloe told both Channel 4 and CPL after filming, but before her series had been aired, that she had been raped.
Chloe said that on one occasion after she had moved in with her onscreen husband, he took the blankets off her while she slept, "and grabbed my breasts and grabbed my bum."
"I was saying no, no, stop, stop that, because I'd been asleep," she said and that she immediately reported the incident to the welfare team.
Lawyers for CPL said Chloe told them she had not been uncomfortable and had felt safe and did not want the welfare team to discuss it with her onscreen husband.
The couple had started having consensual sex, but Chloe said on one occasion she had said "no", after he asked her if they should have sex.
He proceeded anyway, she said.
"He smirked and climbed on top of me, moved my leg… By that time, I'd really given up and I just didn't want him to be angry at me when the cameras came," she said.
"I just lay there, and I stared out the window."
He then recognised she was not participating, she said and asked, "Do you not want this?"
"I said, 'I told you I didn't want this,'" she told the BBC, "and he got very angry, and was like, 'You should've screamed and shouted. You should've pushed me off'."
Chloe said he then said to her, "You're making me feel like a rapist."
Lawyers for Chloe's onscreen husband said he challenges details of her account.
They said the sex had started consensually but that Chloe had communicated through her body language that she was no longer consenting and he then stopped immediately. He also denies groping her, they said.
After the series filming finished, Chloe saw the show's psychiatrist and said it was only then that she felt safe enough to talk about what had happened. The psychiatrist told her that her account was one of rape, she said.
"When people think of rape, they don't think of it as just this type of thing. But it is, that's what it is," she said.
The psychiatrist viewed Chloe's allegations as "serious and concerning", CPL's lawyers said. CPL then told Channel 4.
Before MAFS UK was broadcast, Chloe complained directly to Channel 4 about what she says had happened to her, and how it had been handled by CPL.
The broadcaster told her that after a thorough review, it found CPL had followed welfare procedures.
By the time she got this response, the series was already on air. Watching the show had a devastating impact, leaving her with suicidal thoughts, she said.
Lawyers for CPL said they followed their welfare protocols, they took Chloe's concerns seriously during filming and that before she made the rape allegation, she had told CPL all sexual activity was fully consensual. They also said Chloe was supported throughout the process and afterwards and that she didn't ask to be removed from the show, as broadcast.
None of the women we have spoken to have reported their allegations to the police.
"It's not likely that anything will happen," Chloe said.
A third woman, Shona Manderson, appeared in the 2023 season of MAFS UK. Talking to Panorama on camera, she said she deserved better welfare from CPL after she said her partner took things too far during sex.
She was matched with Bradley Skelly, who was at the time a meditation teacher from Grimsby. "Our first kiss was magical," said Shona, who was a performing arts teacher when she signed up to the show.
The couple started having sex. In the filmed discussions with the show's experts, Bradley was very open that he wanted to do things that pushed her boundaries, although he also acknowledged that there were things he understood she would not do.
They had agreed to use the withdrawal method of contraception, Shona said, but she told us that on one occasion her onscreen husband ejaculated inside her without asking her permission.
"I was shocked, I was confused, we said we weren't doing that," she said.
Shona did not immediately tell anyone what had happened. At around the same time the show's experts had begun to pick up on how Bradley was speaking to her in a controlling way - calling him out on screen in front of the show's other couples.
Shona said she later went to get a morning-after pill and was accompanied by a welfare producer.
Lawyers for CPL said the production company spoke to the couple a few days later.
They said Shona told them what had happened and that Bradley had not asked for permission to ejaculate inside of her. Shona later told CPL that she did not have an issue with it, they said.
The lawyers also said Bradley told CPL he had been wearing a condom.
Lawyers acting for Bradley Skelly have subsequently told Panorama he was not.
CPL and Channel 4 decided to remove the couple from the show shortly after the incident. There were concerns the relationship was potentially unhealthy.
Bradley Skelly said he understood Shona had consented to him ejaculating inside her that night.
In a statement he said he categorically denies "any allegations of sexual misconduct" or that he was "controlling".
Their relationship "was based on mutual consent, care and affection," he said.
About a week after leaving MAFS UK, Shona discovered she was pregnant. "I made the choice to go through with an abortion. It was really hard," she said.
Shona said she does not know if the pregnancy resulted from the alleged incident and she said some people within production and welfare treated her well.
Bradley and Shona, who had stayed together for six weeks after leaving the show, separated shortly afterwards.
CPL's lawyers said the company took appropriate measures to safeguard Shona's wellbeing.
Channel 4 said Shona was clear at the time that all sexual contact was consensual.
If someone makes it clear they don't want their partner to ejaculate inside them, and they do it anyway, "that can amount to a… sexual violation", said Baroness Helena Kennedy KC who, as well as chairing the Creative Industries Independent Standards Authority, is a highly experienced criminal lawyer.
She is calling on Channel 4 to bring in external investigators to assess the show's welfare system. She is critical of the format and said she, personally, does not think MAFS UK should be on air at all.
Women often do not immediately report allegations of rape and sexual assault, she said, "because of the sense of shame that you have, that somehow it's your fault".
"It takes a while to come to terms with 'what was done to me wasn't right'."
Prof Helen Wood of Aston University, a media academic, has carried out a three-year study into reality TV and has spoken to some former MAFS UK cast members as part of it.
She said the highest risk is on shows where people are taken into an "unnatural" environment, where "their contact with the outside world is removed from them."
"The bubble of the show assumes that there will be, kind of intimacy," she added, "and that is a dangerous situation."
Channel 4 had said decisions were taken on a "case by case" basis, taking into account the information available at the time.
It said the three women who have spoken to Panorama gave repeated assurances they felt safe, happy and wanted to continue in the process. It also said many cast members have been explicitly or publicly complimentary about the care they received on the show.
In Monday evening's statement, the channel's chief executive Priya Dogra expressed sympathy to contributors "who have clearly been distressed after taking part in Maried at First Sight".
She said the allegations were disputed by those accused, adding that she believed the broadcaster had "acted quickly, appropriately, sensitively and with wellbeing front and centre" when concerns were raised.
