In 2018, the controversial Russian art project "DAU" scandalised Germany with its plans to rebuild the Berlin Wall and offer visitors an immersive experience of daily life behind the Iron Curtain.
Eighteen months later, "DAU" has again caused shock and outrage in the German capital with the world premiere of its film "DAU: Natasha" at the Berlin film festival.
Aside from debts, the films are now all that is left of "DAU," director Ilya Khrzhanovsky told AFP on Wednesday.
Yet the films have proved as scandalous as the rest of the project, with Golden Bear candidate "DAU: Natasha" prompting furious reactions in the Berlin press.
The daily Tagesspiegel called the film, which was shot over several years in which those involved were living in a mock-up Soviet world, a "dangerous game between fiction and reality."
"When conceptual chaos collides with real chaos, it is difficult," Khrzhanovsky admitted on Wednesday.
One film critic at local broadcaster RBB refused to write a traditional review of the film, pointing to accusations of abuse against Khrzhanovsky.
Following a harrowing interrogation scene in which a woman is sexually abused on screen, Fabian Wallmeier wrote that he "left the cinema with my knees shaking."
Chaos has never been far from the "DAU" project, which blurs the lines between theatre, cinema and anthropological experience.
"We were cancelled twice in Berlin and lost a lot of money. We are covering debts and did not have the money to go to London," Khrzhanovsky told AFP.
After authorities rejected its plans to rebuild the Wall in Berlin in late 2018, "DAU" eventually launched a similar immersive experience in Paris early last year.
The project invited paying customers over the age of 18 to embark on a "journey" into the Soviet Union through films, sets, concerts and conferences, and attracted nearly 40,000 visitors despite numerous hiccups.
Yet the project began over a decade ago, and was initially intended to be little more than a biopic of Nobel Prize-winning Russian physicist Lev Landau.
It rapidly escalated into a sprawling experiment, in which 400 volunteers were filmed living in a recreation of a Soviet scientific institute in Ukraine.
Those who participated did so "because they decided to be there, not because it is a job or because they want to be famous," Khrzhanovsky said.
In two years of immersion, Khrzhanovsky and co-director Jekaterina Oertel shot around two dozen films, one of which was "DAU: Natasha."
The film, which is up for the top prize in Berlin this week, focuses on Natasha, who took part in the Ukrainian experience for several months in 2010.
She even met her husband on the project, the directors recalled with amusement.
"She went back to her prior life like the others -- except those who decided they are now actors," Khrzhanovsky said.
On Wednesday, though, Natasha Berezhnaya was in Berlin to answer questions about the film which bears her name.
"We were free, we knew what we were doing and we shot these scenes with full independence," she told reporters, countering rumours of abuse and harassment which have swirled around the largely improvised project.
According to Khrzhanovsky, the only rule he observed was to warn actors when a scene may include violent or sexual acts.
"It's a journey... about a woman who is beaten and humiliated but still standing, just like millions of Russian women up to this day," Oertel told AFP.
"Natasha is Natasha placed in another time, she's herself, this is how she behaves. It's for you to decide if it's fiction or real."
With another "DAU" film -- "DAU: Degeneratsia" -- also featured on the Berlinale programme, Khrzhanovsky too believes the film festival is finally a chance for Berliners to "have their reactions" to his controversial project.