Allegations of sexual assault have pitted Russia’s boldest political artist, Pyotr Pavlensky, against its boldest political theatre group, Teatr.doc, dividing public opinion this week.

“The regime wants to remove Pavlensky,” read the headline of an opinion piece on the website of Snob magazine. “Pavlensky is no martyr,” read another on the same site.

Pavlensky, renowned for stunts such as nailing his scrotum to Red Square and cutting off his earlobe to protest against what he calls a brutal police state, said on Monday that he had fled Russia after being detained and questioned for nine hours over an alleged sexual assault.

The complaint, also concerning his partner Oksana Shalygina, was filed by the actor Anastasia Slonina in December. Slonina regularly appears at Teatr.doc. The theatre company has repeatedly been evicted by authorities after running plays ridiculing Vladimir Putin and the Russian government.

On Tuesday, police opened a separate criminal case for battery against Pavlensky, the state news agency TASS reported, over a dispute he had with Slonina’s one-time boyfriend, the actor Vasily Berezin, in October.

Pavlensky and members of the theatre had previously accused Berezin of abusing Slonina.

Pavlensky admitted to the Guardian that he hit Berezin during a confrontation at the theatre, but denied that he was the attacker shown in a security camera video uploaded by the Teatr.doc director Yelena Gremina. In the video, one man hits another man several times and kicks him as another person holds him on the ground.

The artist also admitted he and Shalygina had intimate relations with Slonina once in December, but denied the sexual assault allegations.

“There was no violence, nothing even close, and we left as friends,” Pavlensky said, and accused Slonina of working with the authorities to frame him.

But members of Teatr.doc have defended the actor and denounced Pavlensky, who has previously worked with the theatre.

Vsevolod Lisovsky, a director at Teatr.doc, said he brought Slonina to the police the day after her night with Pavlensky and Shalygina where she spoke to investigators for more than five hours. Slonina declined to comment when contacted by the Guardian.

Pavlensky and Teatr.doc are both darlings of the liberal intelligentsia and the news sparked a fierce debate online.

Some said Pavlensky was being “set up” and “provoked”, while others accused the artist of using the narrative to cover up his abuse.

A few accused Pavlensky, who in 2015 demanded the “harshest possible sentence” after he set fire to the doors of the FSB in a political stunt, of betraying his professed ideals by fleeing the country.

Pavlensky said he wasn’t willing to go to prison this time because he didn’t actually commit the crime, and he was worried their two young daughters would be sent to an orphanage if he and Shalygina were convicted.

Pavlensky holds a petrol can in front of FSB headquarters in 2015. Photograph: Reuters

Marat Guelman, a well-known figure in the art world and friend of Pavlensky, claimed the authorities were attempting to discredit him, comparing the case to that of the groundbreaking film-maker Sergei Parajanov who was persecuted in Soviet times with a dubious rape sentence.

That authorities “were able to set two fighters of the regime against each other is a huge success”, Guelman said.

But Alexander Gorbachev, an editor at the popular independent news site Meduza, said he was dismayed by how quickly acquaintances had written off Slonina’s allegations.

“To say that it says a lot about the state of the discussion about sexual violence or women’s rights in Russia would be a stretch, but it still does say something,” he said. “Here a lot of people from my own social circle find it completely normal to write stuff such as ‘you know, this girl performs topless in her theatre, makes you think if she indeed is so innocent’.”