Kirill Serebrennikov entered court this week in a black T-shirt bearing a message for Russia, a quote from Nikolai Gogol’s Dead Souls: “Rus’, what do you want from me?”

It was an apt question from Russia’s leading avant-garde director, who faces a tortuous, months-long criminal trial seen as a bellwether for artistic freedom in the country.

Serebrennikov has been charged with embezzlement and faces 10 years in prison. Supporters have compared his trial to the purge of directors during the Soviet Union and the censorship of leading writers under the Tsars.

“People of culture have always held the most dangerous position in Russia,” Liya Akhedzhakova, a celebrated actor who starred in Soviet classics like Office Romance, told the Guardian in court on Tuesday. “They are the first to be targeted.”

Prosecutors claim that Serebrennikov and three co-defendants embezzled $1.2m (£937,000) from the Studio Seven theatre company from 2011-2014. The defence claims the money was spent on productions.

Critics think Serebrennikov’s problems have more to do with his politics than with money. The virtuoso director has made his name directing plays and films that challenged social norms, in a career that has been championed by some Kremlin officials but has also earned him powerful enemies.

The Student, a 2016 production about a teenager who wields religion to subdue his classmates and teachers, was seen as a searing critique of the Orthodox Church. Nureyev, a 2017 ballet directed by Serebrennikov, saw its debut at the Bolshoi theatre delayed amid concerns over its overt portrayal of the dancer’s homosexuality.

Now the man who created a hotbed of avant-garde theatre at Moscow’s Gogol Centre spends his days in court parsing expense reports.

During a seven-hour court session on Tuesday, he elicited laughs from the gallery when he described how he confirmed a request to purchase a musical instrument. “Ura! Let’s buy a piano!” he recalled saying.

He said he was more focused on productions than procurements.

“I was the artistic director,” he told Moscow’s Meshchansky Court court on Tuesday. “I didn’t know about the accounting side.”

The case has become a cause célèbre among Russia’s intelligentsia. In court you are likely to run into a smattering of film and movie stars, along with prominent journalists monitoring the process.

On a recent Tuesday, the 80-year-old Akhedzhakova was nodding off in the front row as a defence lawyer spent hours reviewing employee salaries. Next to her sat Chulpan Khamatova, the Good Bye Lenin! star who has spoken out in Serebrennikov’s support.

“It’s like they’ve never worked in the theatre before,” sighed Akhedzhakova after the hearing.

Other attendees have included the acclaimed novelist Lyudmila Ulitskaya and the actor Kseniya Rappoport. A number of foreign artists have also spoken out in support of Serebrennikov, including actress Cate Blanchett and German theatre director Thomas Ostermeier.

But as the trial goes into months of detailed inspection of financial documents, an element of fatigue has set in. The court was standing-room only on its opening day. Now there is plenty of space on the back benches.

“This part of the process is less dramatic,” said Zoya Svetova, a prominent journalist and human rights activist who attended court on Wednesday. “People have expressed their opinions. And now they’re waiting to see how this ends.”

Breaking the monotony is one reason for the rotating cast of stars arriving in support of Serebrennikov and his co-defendants Aleksei Malobrodsky, Sofia Apfelbaum, and Yuri Itin.

It may also explain the new quotations every day on Serebrennikov’s shirt, which are each taken from his productions. One message read “Burn,” a reference to his staging of Alexander Pushkin’s The Little Tragedies. Another reads “sink everything,” as Faust tells Mephistopheles in Pushkin’s A Scene from Faust. A third says “Deus conservat omnia” – God preserves everything – the slogan displayed in neon on stage during Serebrennikov’s Akhmatova. Poem without a hero.

Others have sought their own ways to keep the case fresh.

Mikhail Zygar, a prominent Russian journalist and author, has developed a Moscow walking tour narrated by Serebrennikov.

Serebrennikov is under house arrest, but is allowed out for two hours every day, and the walking tour follows the route that the author usually takes.

Zygar said that he wanted to release the walking tour during the trial in order to let Russians know that “it could happen to any one of us” and because “what was shocking can start to seem normal.”.

In the tours, Serebrennikov tells the history of his neighbourhood in Moscow, which was home to cultural icons such as Mikhail Bulgakov, Boris Pasternak, poet Sergei Yesenin, or philosopher and writer Alexander Herzen.

“The stories of each of these cultural figures resembles the personal story of Kirill, every writer or artist has his own conflict with the authorities,” Zygar said.

Then he added: “Hopefully, his story is not going to be as tragic as some of the others.”