Channel 4’s chief executive has stood by the broadcaster’s treatment of concerns raised by contestants on Married at First Sight, as she said she was “deeply sorry” for the distress of female participants making allegations of rape and sexual misconduct.

Priya Dogra said she believed the channel had acted appropriately at the time of the allegations, but that she had commissioned an external review to ensure the show was safe for those taking part.

She spoke as a committee of MPs demanded answers from the broadcaster and Ofcom, the media regulator, over what they described as the “horrifying allegations” made about the hit show.

Married at First Sight (MAFS) UK features single people being matched by experts and then “marrying”, with the couples meeting for the first time on their wedding day.

An edition of the BBC’s Panorama aired allegations by two women that they had been raped by their on-screen husbands on the show. They have not been named. A third woman, who agreed to be identified, Shona Manderson, accused her on-screen husband of subjecting her to a non-consensual sex act. All the men deny the claims.

The BBC has since been contacted by a number of former MAFS UK participants raising concerns, according to its culture and media editor, Katie Razzall.

The Metropolitan police also reiterated its appeal to anyone with allegations of abuse during the show to come forward. “We are ready to listen to them,” said the Met assistant commissioner Matt Twist. “We are ready to investigate.”

The force is already in touch with Channel 4 and CPL, the independent production company that makes the show for the broadcaster.

Speaking at Channel 4’s annual report, Dogra said that while she believed the broadcaster had acted appropriately, she had ordered external reviews to take a “second look”, given she only took up her role in March.

“I have watched the programme and heard the women’s accounts, which are very troubling,” she said. “Their distress is clear, and for that I am, of course, deeply sorry.

“Welfare across all our programmes is hugely important to us, and is a primary concern. However, I’m sure you, you’ll appreciate that Channel 4 cannot investigate the specific allegations against the men – which they have denied – nor can I comment on them in any way. We are a broadcaster, not an adjudicator, and allegations of this type are investigated by other bodies, including when complaints are raised by the police.

“I do believe that a handling of concerns raised at the time was appropriate, but as I took up the role only recently, I wanted this looked at again.”

Ian Katz, Channel 4’s chief content officer, said: “I am very confident that, based on the knowledge that we had at the time, that we made the right decisions, that we ensured that women involved were kept safe when any issues were raised to us, that we gave them the appropriate support – and that we took the right decisions through the production process and beyond that.

“But obviously these are serious allegations, and it’s clearly right to take a second look at them and make sure that we got it right at the time and more importantly to look at whether there’s anything we need to learn about how to make the show in future.”

The former Channel 4 chief executive Alex Mahon has already described the rape allegations as “very serious and concerning”.

MPs on the Commons culture select committee have now written to Channel 4 about its handling and to Ofcom about its involvement, as well as the timeline for launching its own investigation into the allegations.

Caroline Dinenage, the Conservative chair of the committee, said: “The horrifying allegations about Married at First Sight raise serious concerns over whether enough is being done to protect people taking part in reality television. Both Channel 4 and Ofcom, as the broadcasting regulator, have urgent questions to answer.”