A Moscow court has acquitted one of Russia's top human rights activists of criminal charges of defaming the Kremlin-backed leader of Chechnya.

In a surprise decision, the court ruled Tuesday that Oleg Orlov was only expressing his opinion when he said Ramzan Kadyrov was responsible for the murder of a fellow activist.

The court said Orlov did not accuse Mr. Kadyrov of direct personal involvement in the killing when Orlov said the Chechen leader created an atmosphere that led to the murder.

Russian courts seldom rule against political leaders.

Orlov heads the human rights group Memorial. He says the court's ruling defends a Russian citizen's right to speak his mind. Orlov could have faced three years in prison if convicted.

Mr. Kadyrov's lawyers say they will appeal.

The case centered on the 2009 kidnapping and murder in Chechnya of Memorial human rights activist Natalia Estemirova. Her killers have still not been found.

Human Rights Watch calls Tuesday's court decision a positive sign for justice and freedom of expression in Russia.