Two past Married At First Sight UK contributors have claimed they were raped by their on-screen husbands on the show.
Another woman said she faced sexual misconduct from her husband while filming the Channel 4 social experiment, according to a BBC Panorama investigation.
Channel 4 said the allegations were "wholly uncorroborated and disputed".
However, the broadcaster later announced it had removed all episodes of the show from its streaming services following a small number of “very serious allegations of wrongdoing”.
It follows an external review commissioned in April into the welfare of participants on the show, which involves couples marrying after meeting for the first time on their wedding day and living together.
The three unnamed women have raised major concerns about the safety and welfare of female cast members on the reality show.
The allegations will be explored in the documentary: The Dark Side of Married at First Sight, which will be shown on Monday at 8pm on BBC One. The men accused of the sex attacks deny the allegations.
The Panorama investigation will claim that producers have left vulnerable participants at risk of harm.
The channel and CPL - the independent production company that makes the series - say their welfare protocols are robust and comprehensive.
“In April, Channel 4 was presented with serious allegations of wrongdoing against a small number of past contributors, allegations that we understand those contributors have denied,” the broadcaster said in a statement on Monday.
“The channel is mindful of the privacy and continuing duty of care towards all contributors, and cannot comment on or disclose details of those allegations.
“Related to those allegations, Channel 4 was asked to respond to claims of failures in welfare protocols. Channel 4 believes that when concerns related to contributor welfare were raised through existing welfare and production protocols, prompt and appropriate action was taken, based on the information available at the time.
“Channel 4 strongly refutes any claim to the contrary.”
BBC Panorama presenter Noor Nanji claims to have spoken to the three women who have accused their onscreen husbands of sexual misconduct.
It is understood that none of the couples are still together.
The BBC has not disclosed when and where the alleged sex attacks took place.
The show, which has aired ten series in the UK so far, sees matchmakers and relationship experts join strangers together in the hopes of finding love. The newest series
At the end of their eight weeks together, the couples are asked if they want to stay married.
Most of the couples end up splitting, but it has spawned several successful relationships. In the UK version of the show, the marriage success rate is around five to seven per cent.
Channel 4’s recently appointed CEO, Priya Dogra, said: “It would be wholly inappropriate for me to comment on what are very serious allegations made against some MAFS UK contributors.
“Those allegations – which I understand are disputed by the contributors accused – are not something that Channel 4 is in a position to adjudicate on. We are also mindful of our ongoing duty of care to all contributors, and the need to preserve the anonymity and privacy of all involved.
“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.
“Nevertheless, because we aspire to the highest standards of contributor welfare, I felt strongly as Channel 4’s new CEO that it was right that we look again at how we handled issues raised at the time and ask whether changes should be made to further strengthen contributor welfare.
“That’s why last month I commissioned an external review of contributor welfare on MAFS UK. That review will report to me in the coming months.
“We take these issues very seriously and are committed to ensuring that we continue to lead the industry in our duty of care for contributors.”
The broadcaster said the two-part review will consist of law firm Clyde & Co investigating welfare protocols and handling of the claims, while former BBC One Controller Lorraine Heggessey will lead an examination of current contributor welfare measures.
It expects the review to report in the coming months and will share a summary of findings and recommendations.
CPL was approached for comment by the Press Agency.
If you've been the victim of sexual assault, you can access help and resources via www.rapecrisis.org.uk or calling the national telephone helpline on 0808 802 9999
