The former soap actor Roxanne Pallett has become the second contestant to leave the Celebrity Big Brother house without being evicted, after alleging her co-star Ryan Thomas punched her repeatedly in the stomach.

The media regulator Ofcom received more than 11,000 complaints from viewers after Thursday’s episode of the Channel 5 show, in which the ex-Emmerdale actor Pallett tearfully told Big Brother she was hurt by the incident and wanted to sleep in a separate bedroom.

The producers gave Thomas, a former Coronation Street actor, a formal warning. This prompted viewers to complain to Ofcom, with some arguing he had only been play-fighting.

“Roxanne has decided to leave the BB House. The remaining housemates have been informed,” a Celebrity Big Brother spokesperson said, adding there would be no further comment.

The incident allegedly took place in the kitchen of the Big Brother house. Pallett said afterwards: “He actually punched me like a boxer would punch a bag. And we weren’t play-fighting, there was no banter; it wasn’t a joke.”

Upon receiving a warning in the show’s diary room for breaking show rules, Thomas apologised but said he had not intended to hurt Pallett. “I think we both know, and Roxanne, that there was no malice or anger in anything I did.”

The show’s producers told Pallett footage of the incident was being reviewed and the matter was being “taken very seriously”. Ofcom has said it is assessing the complaints before deciding whether to investigate.

The current series of Celebrity Big Brother got off to a tricky start after Stormy Daniels, the pornographic film actor who claims to have had an affair with the US president Donald Trump, pulled out at the last minute. She had been billed as one of the show’s biggest stars.

Another contestant was then removed for using racist language. Brazilian contestant Rodrigo Alves, known as the “human Ken doll”, used the N-word twice to describe his sexual preferences to another contestant.

The Channel 5 controller, Ben Frow, has previously hinted he is considering cancelling the series altogether after the broadcaster’s contract to air the programme expires at the end of this year.