The artists who crossed the line

On a chilly Moscow morning last November, 10 plainclothes policemen broke into the Moscow apartment where Oleg Vorotnikov and Leonid Nikolayev were sleeping. Screaming at everyone to stay on the ground, the officers handcuffed the two men, pulled plastic bags over their heads and threw them into a police van. They drove north for 10 hours while police allegedly kicked and abused the two men, who have been held in a pre-trial detention centre in St Petersburg until this week. But Mr Vorotnikov and Mr Nikolayev are not drug dealers or dangerous murderers on the run – they are artists.

The two men are part of Voina, a radical art collective that has infuriated the Russian authorities with a series of increasingly audacious stunts, and whose jailing has caused concern in Russia about a return to a Soviet-style censorship of the arts. Over the past three years, the group's installations and performances have included organising the mock execution of migrant workers in a Moscow supermarket, an impromptu expletive-filled punk rock performance in a courtroom, throwing live cats at McDonald's cashiers and painting an enormous penis on a bridge in St Petersburg.

The group first came to prominence in February 2008, two days before the carefully choreographed elections that brought President Dmitry Medvedev to power. About 12 activists, one of whom was a pregnant woman, entered the Biology Museum and staged an orgy.

Meanwhile, the group's leader and chief ideologist, the bearded Alexei Plutser-Sarno, donned a top hat and unfurled a banner that said: "Fuck for the Teddy Bear Heir!" The slogan played on Mr Medvedev's surname, which is derived from the Russian word for "bear", and poked fun at what the group said were "farcical and pornographic elections" in which Mr Medvedev was to inherit Vladimir Putin's "throne". The group was charged with "disseminating pornography" and so began a life underground, where the core group of activists eschewed mobile phones and moved apartments frequently to evade the authorities.

Soon, the stunts became bigger and harder to ignore. The most notorious Voina action was last June, when several members of the group painted a penis on the Liteiny Bridge in St Petersburg. Evading and fighting off security, the 65-metre high image was completed just before the bridge opened, as it does each evening to let ships pass through. The penis "erected", directly facing the St Petersburg headquarters of the FSB, the KGB's successor. The group called the artwork Dick Captured by KGB.

Mr Plutser-Sarno, 48, said he left the apartment where the other group members were arrested the day before the raid and has been on the run ever since. He claims that he comes and goes from Russia by slipping across the porous border with Kazakhstan and that he rarely spends consecutive nights in the same place. It is unclear how much of this is true, but he only agreed to speak with The Independent via Skype and refused to disclose his location. "It wasn't easy to find us and our Russian cops are corrupt, they can't be bothered to look for impoverished artists," Mr Plutser-Sarno said. "They prefer to carry out criminal activity and go after businessmen from whom they can steal money."

The most controversial of all was Voina's final stunt before the arrests, which the artists called "Palace Revolution". Members overturned seven police cars, some of them with officers inside, at St Petersburg's Palace Square one night last September. Mr Pluster-Sarno denies that with this last radicalisation, the group's work attained a criminal element.

"If the artists consider their action a piece of art, if the experts along with the audience agree with it, what it is then? Art or crime? We struggle against the authorities who are criminal indeed." Those same authorities have begun to clamp down hard on Voina. Mr Vorotnikov and Mr Nikolayev have been charged with hooliganism, which carries a sentence of up to seven years in prison, while Mr Plutser-Sarno has been charged with organising a criminal group, which could land him a sentence of up to 20 years.

Last month, a judge in St Petersburg refused bail for Mr Nikolayev and Mr Vorotnikov, despite that the street artist Banksy had offered £80,000 as a surety after reading about the group's plight. This week, the pair was finally released on bail after another hearing accepted that the delay between the arrest and court case was too long. But the charges still stand.

Not everyone in the Russian art community approves of Voina, but there has been a certain solidarity after their arrest, and the Dick Captured by KGB has been nominated for a prestigious contemporary art prize.

"Voina has inherited the tradition of the Russian futurists from the early 20th century. This isn't just art, but revolutionary art," said Olesya Turkina, a curator and research fellow at the Russian Museum in St Petersburg. "The Dick Captured by KGB was an absolutely genius artwork that demonstrates the phallic, patriarchal character of our state." She admitted that overturning police cars was more difficult to justify, but said it is "absurd" that the hooliganism charge on which the arrests were made is the same used against skinhead groups who perpetrate racist attacks.

Ms Turkina welcomed the release of the two artists on bail but said it was very worrying they would still have to face trial. "After perestroika we had 10 or 15 years of real artistic freedom, but now there are very worrying signs again," she said.