MOSCOW: A Russian court on Tuesday freed a mixed martial arts (MMA) champion from the Northern Caucasus after convicting him of involuntary manslaughter for killing a teenager, in a case that roused nationalist protests.

Rasul Mirzayev, a 26-year-old fighter from the mainly Muslim region of Dagestan, hit 19-year-old Ivan Agafonov in August 2011 after an argument outside a Moscow night club.

Although Agafonov seemed only slightly injured immediately after, he fell into a coma and died within a few days.

Mirzayev was an undefeated Russian champion in the featherweight category of MMA—an often bloody mixture of wrestling and boxing hugely popular in Russia—at the time of his arrest.

The long-running case was seen by Russia’s nationalists as skewed by the investigation in favor of the Dagestani man after his charge was changed from murder to the lighter involuntary manslaughter, with some experts arguing that Agafonov died because of hitting his head on the pavement.

In a Moscow court on Tuesday, judge Andrei Fedin found Mir-zayev guilty and sentenced him to two years of restrictions to his freedom in his hometown Kizlyar, but not prison.

The judge ordering him released after taking into account his yearlong stay in jail pending the trial, and his family situation.

“Shame!” some people in the audience yelled as the judge said Mirzayev was to be freed immediately. “The scum is being let go!” another person yelled. “The life of a Russian costs nothing here!”

Amid some commotion outside the courthouse, police detained nationalist leader Dmitry Dyomushkin, he said on Moscow Echo radio, calling the case “political”.

Other commentators questioned why causing someone’s death qualifies as a lesser crime than dancing in a church, referring to the two-year prison sentence imposed in August against members of female punk band Pussy Riot.

Fearing that Mirzayev might be attacked by an angry mob, security led him to a car from the court’s back entrance and drove to a different neighborhood, where he met his family, a police source told Interfax news agency.

Some right-wing websites called on followers to go to the central Manezhnaya Square to protest the “anti-Russian” ruling and police went on high alert to block it off, as well as closing access to Red Square, Russian media reported.

Russian authorities have treaded carefully around nationalism-tinged issues ever since thousands of right-wing football fans staged a violent rally near the Kremlin in 2010 to protest at the way police handled a Russian fan’s death in a fight with some young men from the North Caucasus.