Two women have alleged they were raped during the filming of Married at First Sight UK, one of Channel 4’s biggest shows, and a third alleged she was subjected to a non-consensual sex act.

The show did not do enough to protect them, the women told an edition of the BBC’s Panorama outlining their allegations.

The programme alleged Channel 4 was aware of some allegations before broadcast and that the episodes featuring the women involved had been available on its streaming service until recently.

On Monday afternoon, Channel 4 said it had removed all episodes from streaming and linear services, alongside Married at First Sight UK social channels.

In the reality show, known as MAFS, single people “marry” strangers who they meet for the first time on their wedding day, though the marriages are not legally binding.

Channel 4 said it was presented with “serious allegations” in April against a small number of past contributors, which it understood were denied by those contributors. It said that when concerns related to contributor welfare were raised through existing welfare and production protocols, “prompt and appropriate action was taken”.

“Channel 4 strongly refutes any claim to the contrary,” it said.

Lawyers for CPL, the independent production company that makes the UK version of the show for Channel 4, told the BBC that its welfare protocols for contributors were “gold standard” and that it acted appropriately in all these cases.

According to the Panorama report, one woman said her onscreen “husband” raped her and threatened her with an acid attack.

She alleged that sex with her onscreen husband soon turned violent and she “kept saying stop”. She told Panorama she had been 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.

Lawyers acting for the woman’s onscreen husband told the BBC he denies rape.

Lawyers for CPL said the woman did not tell the company about her partner saying she “can’t say no” to him and that the acid-throwing remark had been reported as a passing comment, not a threat. They said CPL acted immediately once the woman felt unsafe.

A second woman alleged she told both Channel 4 and CPL, before broadcast, about being allegedly raped by her onscreen husband, but her episodes were still aired.

Lawyers for CPL said they followed welfare protocols and took the concerns seriously. They said that before she made the rape allegation, she had told CPL all sexual activity was fully consensual.

A third woman accused her onscreen husband of sexual misconduct.

Channel 4 said the show was produced “under some of the most comprehensive and robust welfare protocols in the industry”, including thorough background checks, a code of conduct, daily contributor check-ins and a specialist welfare team.

Priya Dogra, Channel 4’s new chief executive, launched an external review of contributor welfare on the show last month. It will look at the handling of any claims and whether welfare protocols should be updated.

“I want to express my sympathy to contributors who have clearly been distressed after taking part in Married at First Sight UK,” Dogra said. “The wellbeing of our contributors is always of paramount importance.

“On the claims that Channel 4 may have failed in its duty of care, I believe that when concerns about contributor welfare were raised, and based on the information available at the time, Channel 4 acted quickly, appropriately, sensitively and with wellbeing front and centre.”