Moscow (AFP) - A Russian court granted parole Monday to Oyub Titiyev, the head of the Chechen branch of rights group Memorial convicted this year on controversial drug charges, the NGO said.

The court "agreed to a parole request for Titiyev. Now he must be released within 10 days," Memorial representative Oleg Orlov told AFP.

The 61-year-old was sentenced for drug possession in March to four years in a penal colony in a case condemned by Amnesty International and other global rights groups.

Titiyev's lawyers said the case was connected to his investigations into the secretive prison system of a republic notorious with rights abuses.

Observers say drug charges have been used repeatedly in the past to silence critical journalists and rights workers in the region.

The release came as authorities in Moscow faced public pushback against the arrest of an investigative reporter named Ivan Golunov on separate drugs charges.

But Orlov told AFP this was not connected to the Chechen court's decision.

"We do not see any connection with the detention of Golunov on drugs charges. We have been waiting for this decision for a long time."

Memorial speaks out about human rights violations in Russia and has accused the Chechen leader of overseeing a "totalitarian" regime that uses kidnappings and torture.

Titiyev's predecessor as the regional leader of Memorial, Natalya Estemirova, was kidnapped and killed in 2009. The rights group said the killers were acting on the orders of local authorities.