Activists who brought Navalny to Germany call his detention a crime

BERLIN, Jan 18 (Reuters) - The head of the activist group that brought Alexei Navalny to Germany for life-saving treatment after his poisoning said it was a "crime" that Russia had detained the Kremlin critic on his return to Russia.

Navalny was arrested at Moscow airport on Sunday evening after he flew home for the first time since being poisoned in Russia with a military-grade nerve toxin last summer.

Jaka Bizilj, head of the Berlin-based charity Cinema for Peace that arranged for him to be flown from the Russian city of Omsk to the German capital for treatment, said the decision to arrest Navalny, an outspoken opponent of President Vladimir Putin, was a political act.

"It really was just luck that he survived at all," Bizilj told Reuters on Monday. "To get arrested again upon his arrival, and get sent to jail: that is the worst Russia can do in the eyes of the world.

"He's still not fully recovered. And to put him in prison in this condition is an additional crime," he added.

Navalny's detention was ordered by Moscow's prison service in relation to alleged violations of a suspended prison sentence in an embezzlement case he says was trumped up.

Bizilj said democracies and Western countries had a responsibility to make sure Russia paid a price for its treatment of Navalny.

"There should be a kind of sanction," he said, adding that Germany should reduce its dependency on Russian gas, including by cancelling the Nord Stream 2 gas pipeline being built from Russia to Germany under the Baltic Sea.

"So if you kill people, if you don't allow democratic elections, then I think there needs to be a reaction and it needs to cost you money," he said. (Reporting by Thomas Escritt; Editing by Giles Elgood)