Senior staff on Married at First Sight UK had an "unhealthy" focus on whether cast members were having sex, former workers on the show have told BBC News.
Producers would deliberately try to make contestants angry or upset for the sake of generating watchable drama, they say.
The former workers on the Channel 4 show have spoken to the BBC following a Panorama investigation into Married at First Sight UK (MAFS UK). Two former cast members say they were raped by their on-screen partners, and a third alleged a non-consensual sex act. Their on-screen partners have denied all the allegations against them.
Lawyers for CPL, the production company which makes MAFS UK, say the latest allegations are from a small minority of former workers, and the company's "commitment to welfare... is evidenced by the high consecutive return rate of crew across the MAFS series".
Channel 4 says contributor welfare is "always our primary concern across all productions".
The fresh claims come after a difficult week for the show. All episodes have been removed from Channel 4's streaming service, a major sponsor has pulled out, and the fate of the latest series - which has been filmed but not broadcast - is uncertain.
The format of MAFS UK sees single people agree to "marry" total strangers, after meeting for the first time at their mock weddings.
But according to several of the workers we spoke to, there was an emphasis on sex from the outset of filming a new series.
Most of those we spoke to have requested to remain anonymous, as they still work in the TV industry.
One, who is happy to be named - Soraya Spiers - calls the culture on the show "toxic from the top down".
"On the wedding night, there's an expectation, for those of us who were working on the show, that you should get some sort of hint if the couples are going to sleep together," she tells BBC News. "Even though they've only known each other for two seconds by that point."
Another former worker, who worked on MAFS UK for several years and attended multiple filmed set-piece events, says she raised concerns that some couples might not want to share a bed on the first night.
"They were alone with a stranger, and they're not really married," she says.
She claims a senior member of the production team told her: "Don't you get it? We want them to sleep together."
Crew members made bets on who would sleep together first, says the former worker: "They would high five each other when [the contestants] did."
The bets were not for money, she adds, but "it was clear to [the crew] that this was all a joke".
CPL's lawyers say the allegation that staff took bets on whether contestants would have sex "is not something which our client recognises at all".
The focus on intimacy continued as the filming progressed, former workers have told us.
Senior producers would express concerns if a couple were not having sex, according to one worker. "It wasn't good for storylines," they say.
The emphasis on sex was "unhealthy", adds Spiers.
"You could argue that's the same in real life, but if you meet someone on a date, you can leave if you need," she says. "Putting it in the framework of a TV show makes it much harder to just walk away."
Lawyers for CPL say contributors are not pressured in any way or expected to have sex. Cast members are informed there is no expectation to share a bed on their wedding night and alternative sleeping arrangements can be facilitated, they add.
One former worker says she felt cast members were "manipulated", even by the standards of reality TV.
It is not unusual for reality TV producers to try to control content, but MAFS UK's content focuses on one of the most sensitive topics of all - sex and intimacy.
"The premise of the show is people finding love, but that isn't what viewers want, that's boring to watch and gets icky," says Spiers. "They're looking for fireworks, clashes and drama."
Other former workers claim producers manufactured confrontations between cast members.
"It would be going up to them and saying, 'do you know so-and-so said so-and-so'," one says. "The idea would be to get that person angry."
When friction was particularly high, another says, lots of the crew would gather to watch it unfold.
"It was sickening how into it they were," he said.
We have also heard that production staff were told to "ramp up trigger points".
At one of the show's set-piece dinner parties, a former worker claims she saw cast members plied with alcohol.
"That is not gold-standard welfare," she says.
CPL's lawyers have told the BBC that alcohol intake during dinner parties is limited and overseen by executive producers and the welfare team. They say it is incorrect that contributors are allowed as much alcohol as they want.
They also say CPL refutes any suggestion it prioritises entertainment over the welfare of contributors or that drama is engineered by production at the expense of the contributors.
Hours before the Panorama edition that would make the rape allegations public, CPL sent an email to current and past crew and contributors telling them that support was available, and giving them advice about talking to the press.
"It was a hush email," and "an effort to damage control," says one worker - while another says it made her "furious".
"These are real people going through trauma, and they should've been protected," she says.
Lawyers for CPL say its email was not intended to silence employees, but to provide support to those affected by the Panorama programme and prevent identification of the female cast members who had made rape allegations anonymously.
Spiers, for her part, replied to the email, accusing CPL of "a spectacular lack of duty of care to both cast and crew".
"I hope the investigation reveals the toxicity that oozes out of every pore of this show and production company," she wrote.
Like some of the other workers we have spoken to, and in common for TV production, Spiers had been on a short-term contract, which ended after five weeks. She turned down an offer of further work on the show, she says.
Lawyers for CPL accuse some of the former workers who spoke to the BBC of having "an axe to grind" against the company.
Some previous contestants, on social media, have been more positive about their experiences on the show. There were also crew members who told us that CPL was a good company to work for.
Channel 4 says: "Contributor welfare is always our primary concern across all productions. Within days of being contacted by the BBC in April, we commissioned an external review of contributor welfare on MAFS UK, which is underway."
It adds that the review "needs to run its course".
Spiers now thinks the show should be decommissioned, as in her view, its model is "completely flawed".
Another former worker calls the show "a car crash waiting to happen".
"I'm not at all surprised at what's emerged," they say. "I could see something like this coming. I didn't want to be there for that."
If you have more information about this story, you can reach Noor by email at noor.nanji@bbc.co.uk
