Chechen rights activist Oyub Titiyev walked free on Friday after being granted parole from a sentence for drugs possession that prompted international condemnation.
Titiyev, the 61-year-old head of the Chechen branch of Russian rights group Memorial, was arrested in January last year, accused of possessing a marijuana-like substance.
Memorial is one of a few rights groups to continue operations in Chechnya, a region under tight control of strongman Ramzan Kadyrov where activists have been beaten up and killed.
In March Titiyev was sentenced to four years in a penal colony but was granted parole this month.
Emerging from prison in the Chechen town of Argun, Titiyev said he "had never ceased his work on human rights," said Oleg Orlov, a Memorial representative who was among those welcoming him.
"We're all happy that our colleague is finally free," said Orlov, while adding Tityev will probably not be able to continue working in Chechnya as before.
"I think it's hardly possible he could work here," Orlov said, while adding that Titiyev will "definitely continue at Memorial" and the group will continue work in Chechnya "in a different way."
"It's very good that they freed Titiyev but it would be good if the practice of planting drugs ended."