The individual is not being named. The alleged victim is also not being named; anyone who makes an allegation of rape is entitled to anonymity by law.
The Panorama programme, broadcast in May, revealed rape allegations from two female cast members on the show, while a third woman alleged a non-consensual sex act. The men involved have denied all the allegations against them.
Channel 4 has commissioned a review into contributor welfare on the show.
Following the broadcast of the Panorama episode, the Metropolitan Police encouraged "anyone who believes they have been a victim of sexual assault" after participating on Married at First Sight UK to contact them.
In a new statement to BBC News, the Metropolitan Police said: "This relates to an ongoing investigation, being led by the Met Police.
"He has since been bailed while enquiries remain ongoing."
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 UK version, which has been running for 10 seasons, is one of Channel 4's biggest shows, with audience figures often topping three million.
In May, Channel 4 pulled all episodes of the show from its streaming service just hours ahead of the transmission of the Panorama investigation.
No decision has yet been made on whether to broadcast the latest series of the show, which has already been filmed.
-BBC






