Europe’s top human rights court urged Russia on Wednesday to immediately release Kremlin critic and opposition leader Alexey Navalny.

The European Court for Human Rights (ECHR) said it was granting an interim measure on an application lodged Jan. 20 by Navalny related to his detention that asked for his release.

In its reply to the ECHR’s queries on safeguard measures in custody, the Russian government said Navalny was being held in a properly guarded facility and his cell was under video surveillance.

It said that he had access to electronic communications via the prison system, allowed to make telephone calls and granted visits by lawyers and members of the public monitoring commission on several occasions.

But following Navalny’s contention that the arrangements were not “sufficient safeguards for his life and health,” the ECHR decided to ask the Russian government for his immediate release.

The ECHR said it regarded the “nature and extent of risk” to Navalny’s life and the “overall circumstances of his current detention,” for the purposes of applying the interim measure.

The 44-year-old anti-corruption activist and a staunch critic of Russian President Vladimir Putin was poisoned with a nerve agent in August.

Upon his recovery, he returned to Russia in January and was immediately detained.

A Moscow court sentenced Navalny to two years and eight months to a penal colony for violating parole regarding a 2014 money laundering case that the ECHR already ruled “arbitrary and manifestly unreasonable.”

Navalny’s arrest and detention triggered widespread protests in Russia and international condemnation from the governments in Europe and the US demanding his release.

The ECHR based in Strasbourg, France, is an international court of the Council of Europe interpreting the European Convention on Human Rights, constituting 47 member states, including Russia./aa