British artist Luke Turner and Finnish artist Nastja Säde Rönkkö tweet to say they intervened and stopped the incident during #IAMSORRY show

Two artists who collaborated with the actor Shia LaBeouf on an art project called #IAMSORRY have spoken out about his alleged rape during the performance earlier this year.

In an interview with Dazed magazine, LaBeouf wrote that a woman had raped him during one performance of the piece at a Los Angeles art gallery in February.

“One woman who came with her boyfriend, who was outside the door when this happened, whipped my legs for 10 minutes and then stripped my clothing and proceeded to rape me.”

His collaborators, British artist Luke Turner and Finnish artist Nastja Säde Rönkkö, said they had intervened as soon as they became aware of the incident and “put a stop to it”.

Both artists posted the same statements on Twitter on Sunday, which they described as “important clarifications” about the art project.

“Nowhere did we state that people could do whatever they wanted to Shia during #IAMSORRY.

“As soon as we were aware of the incident starting to occur, we put a stop to it and ensured that the woman left.”

Turner did not respond when asked if the incident was reported to the police, but said that their collaboration with the actor continued.

Turner later provided more details of the incident after Piers Morgan asked him on Twitter why they had let the [alleged] rapist “just walk away”.

The artist replied: “It wasn’t clear at the time precisely what had happened, & the 1st priority was to ensure everybody’s safety in the gallery …

“She ran out, rather than simply walking away. Beyond that, it’s not my place to comment.”

LaBeouf said that news of the incident “travelled through the line” of people waiting, and reached his girlfriend. He said: “When she came in she asked for an explanation, and I couldn’t speak, so we both sat with this unexplained trauma silently. It was painful.”

#IAMSORRY involved LaBeouf sitting silently behind a desk in a room in LA’s Cohen gallery with a paper bag bearing the legend “I am not famous anymore” over his head. For five days, members of the public queued to be able to sit alone with him in the room with a prop of their choice. Some of the encounters proved confrontational, such as this one shot by Hal Rudnick, host of YouTube channel Screen Junkies, which mocked the art project.

A statement publicising the project said: “Shia LaBeouf is sorry. Sincerely sorry. He will be in situ at 7354 Beverly Boulevard for the duration. Implements will be provided.”

The project was part of a series of performance pieces by LaBeouf in collaboration with Turner and Rönkkö . The actor said the collaboration was a response to his “genuine existential crisis” after he was accused of plagiarism when he lifted portions of a Daniel Clowes short story for a film he was working on. He also wore a paper bag to the Berlin premiere of Lars Von Trier’s film Nymphomaniac, and said he would be retiring from public life.

In an interview with art website aqnb in May, Turner said the collaboration with the Hollywood actor was partly a response to how post-internet artists were using social media to promote their work and how that promotion became the work.

He said: “We’re approaching it from a similar but almost opposite perspective – because with someone who already has a public persona, we’re kind of questioning what that means, where identity and ideas of the self actually lie. With Shia it’s particularly interesting because he’s a method actor, and so he really inhabits those roles, and you do question: where is the true self?”

The collaboration is a meta-narrative on the controversy surrounding LaBoeuf, which could be read on various levels.

For example, Turner wrote a thesis in 2011 called Metamodernist Manifesto. Following his collaboration with LaBeouf, it was republished crediting the actor, not the artist, as the author. This operated as a commentary on the Clowes plagiarism scandal.

Turner told aqnb: “Hollywood still tries to preserve that rarified atmosphere of the Hollywood superstar ... [The project is] a collaboration using social media and performance art – but you get the mainstream celebrity media who are commenting on his outfit that he was wearing, the superficial elements of his persona. We weren’t sure how much they would engage with the actual art he was making.”