A teenage boy lies on a bare iron bed in a rehabilitation centre, so drugged he can barely speak, in a shocking attempt by his parents to cure him -- of being gay.  

The scene is the horrifying climax of a bold new drama playing to packed audiences at one of Moscow's top theatres, though its future is under threat by city prosecutors.

Based on the real-life story of a Russian teenager, the play's sympathetic view of the boy's coming out is testing a Russian law banning any dissemination of "homosexual propaganda" to minors.

Entitled "All the Shades of Blue" -- "blue" is slang for gay in Russian -- it tells the teenager's story of how he first fell for a boy on a school trip.

"I couldn't take my eyes off his body, I was really impressed... I thought he must be a good kisser," the actor says.

But all hell breaks loose when the teenager tells his parents he is gay. "You've really done it now with your coddling -- you've brought up a gay son!" his father, an army officer, berates his wife.
The boy's grandmother takes him to an "exorcist," who promises to free him from the "demon of homosexuality". Then his father pays for a prostitute to try and turn him straight.

When all this fails, the father drives the son one night to a clinic, where he is incarcerated with drug addicts.

Though written by a 29-year-old playwright from the Ural mountains region, Vladimir Zaitsev, who is straight, the piece is playing at one of Moscow's most established theatres, the Satirikon.

Its star director Konstantin Raikin, who declined a request by AFP for an interview, is better known for staging classics such as Shakespeare's "King Lear".

- Over 21s only -

Spectators at the show, which premiered on May 29, must be over 21, part of the precautions taken to ensure it does not break a controversial law banning the "promotion" of gay relationships to minors, signed by President Vladimir Putin in 2013.
Despite its popularity, it is now under threat and "a serious battle has started against the theatre", playwright Zaitsev told AFP on Friday.

"The prosecutors are already studying the play," he said by e-mail, and "the director has been summoned by prosecutors" for questioning.

They are reportedly acting at the request of an obscure group called Art Without Borders who questioned what they called the "swearing, propaganda of amoral behaviour and pornography" in the piece.

According to the Novaya Gazeta opposition newspaper, the prosecutors are also investigating a handful of other shows, including a production of Rimsky-Korsakov's opera "The Golden Cockerel", which alludes to contemporary politics, at the famed Bolshoi.

The liberal Kommersant daily, meanwhile, hailed the Satirikon theatre for putting on "All Shades of Blue", saying it was "little short of heroic" in what it called the current "ubiquitous aggressive craziness".

The audience, on a recent evening, reacted with a standing ovation. "I think a lot of viewers could not control their feelings at the end," said Pavel Solovyov, 29.

But others like 29-year-old Yevgenia, felt the play was overly tragic. "There are loads of people who have more or less an OK attitude" to gay people, she said.

Though the piece contains swearing and sexual language, it is not sexually explicit.

"The young hero of 'Shades' is gay, but he's just a normal, decent boy, and his normality in comparison with animal-like, beastly real life, shows up all that monstrosity," wrote Chastny Korrespondent magazine.

- Based on real events -

Zaitsev told AFP he got the idea from a real-life incident in 2012 when 16-year-old Ivan Kharchenko was forcibly detained in a psychiatric clinic by his father for being gay. The boy was freed after intervention from friends and rights activists.

Zaitsev finished his piece after the gay propaganda law was passed. "To be honest I wasn't counting on a staging in Russia," he said, but was "ecstatic" when he got a surprise call from director Raikin saying he wanted to put on the play.

The young playwright said he wrote the piece for the "intolerant people who are ready to shun their own child, send him to a clinic for treatment, do whatever they can to change him, just to stay within the set of norms that have been dictated to them".

Several gay couples at a recent showing told AFP they had not shared the protagonist's experience, but quickly said this was because they had still not told their parents they are gay.

"We always have to hide," said one of the men, who was afraid to give his name.