International condemnation has followed the decisions by two Russian courts to shut down the prominent human rights group and its sister organisation.
International condemnation of Russia increased on Wednesday following the shutdown of Memorial, a human rights group which drew international acclaim for its studies of political repression in the former Soviet Union.
But the decision by Russia's Supreme Court to revoke Memorial's legal status was followed by another court decision to close down its sister organisation, the Memorial Human Rights Centre.
It comes amid a sweeping crackdown on campaign groups, independent media, and opposition supporters.
The European Court of Human Rights (ECHR), to which Russia is theoretically subject as a member of the Council of Europe, has asked Russia to suspend the decision after receiving a request for interim measures.
The German government slammed the Supreme Court's decision to shut down Memorial, spokesperson Wolfgang Büchner saying it was "more than incomprehensible" and violated international civil rights obligations.
"The trial of Memorial shows once again that repression against civil society in Russia continues to increase," he continued.
British Foreign Secretary Liz Truss said she was "deeply concerned" by the liquidation of Memorial by the courts. "Memorial has worked tirelessly for decades to ensure abuses of Soviet era are never forgotten. Its closure is another chilling blow to freedom of expression in Russia," she tweeted.
US Secretary of State Antony Blinken denounced the "persecution" of both organisations as "an affront to their noble missions and to the cause of human rights everywhere".
In their petitions to shut both groups down, filed to two different courts last month, the prosecutors argued that the organisations repeatedly violated regulations obliging them to mark themselves as "foreign agents".
Memorial and the Memorial Human Rights Center rejected the accusations as politically motivated.
The rulings to shut them down drew widespread public outrage, with crowds of supporters showing up at courthouses on Tuesday and Wednesday despite freezing weather.
Both organisations had been labelled "foreign agents" in previous years, a designation that brings with it additional government scrutiny and strong pejorative connotations.
Alexander Cherkasov, chairman of the Memorial council, called for the "foreign agents" law to be abolished. "It was designed with the aim of strangling civil society. Today, we received another proof of that. The court essentially validated our efforts today," he said.
Russian authorities in recent months have mounted pressure on rights groups, media outlets and individual journalists, naming dozens as foreign agents.
Some were declared "undesirable" - a label that outlaws organisations in Russia - or were accused of links to "undesirable" groups, and several were forced to shut down or disband themselves to prevent further prosecution.