Russia's Supreme Court has begun hearing federal prosecutors' arguments aimed at shutting down one of the post-Soviet world's most prestigious human rights organizations, International Memorial.

The case was brought under controversial 'foreign agent' laws increasingly used to shutter civil-sector and media groups in Russia.

Police detained at least three picketers who appeared separately outside the court in Moscow to express opposition to the closure request.

One held a sign saying, 'We are Memorial,' while another had scrawled on her sign: 'You cannot kill the memory of the people! We survive in poverty, powerlessness and [with] almost no hope.'

Both sides presented arguments to the court before proceedings were adjourned until December 14.

About 50 people were reportedly allowed into the Supreme Court building but the judge warned them not to record the proceedings.

Russian Prosecutor-General Igor Krasnov claims that Memorial International has systematically violated the law by failing to appropriately label its materials.

A separate claim by Moscow authorities targets the Memorial Human Rights Center, the local group that is among Russia's oldest rights groups and works under the umbrella of Memorial International.

A Moscow city court on November 23 heard pretrial arguments in that 'foreign agent' case but quickly adjourned until November 29. The court said it would give Moscow prosecutors more time to address questions presented by the defense lawyers for Memorial Human Rights Center.

Memorial has called the actions of the Russian authorities 'political pressure' and countered that 'there are no legal grounds for liquidation.'

Russia's so-called 'foreign agent' legislation was adopted in 2012 and has been modified repeatedly.

SEE ALSO: Russian Nobel Laureates Warn Against Closure Of Memorial Rights Group

Memorial is among several news outlets and rights organizations to have been labeled 'foreign agents' in what is seen as a historic crackdown on civil society and critics of the government.

The Memorial Human Rights Center was put on the list in November 2015.

International Memorial, a standalone group and the umbrella group for Memorial Human Rights Center and more than 70 other organizations, including 10 operating outside Russia, was added to the 'foreign agents' registry five years ago.

In the decades since it was founded in the dying years of the Soviet Union, Memorial has produced hallmark indicators of the rights situation and elsewhere through lists of political prisoners, and documenting historical and ongoing injustices.

In a joint statement on November 18, two Russian Nobel Peace laureates -- the last Soviet leader, Mikhail Gorbachev, and Novaya gazeta newspaper editor in chief Dmitry Muratov -- said attempts to close Memorial had 'caused anxiety and concern in the country, which we share.'

Marija Pejcinovic Buric, the secretary-general of the Council of Europe, a pan-European rights body, said last week that the 'foreign agents' legislation 'stigmatizes' NGOs, media, and individuals and 'has had a repressive impact on civil society in Russia over recent years.'

Copyright (c) 2018. RFE/RL, Inc. Republished with the permission of Radio Free Europe/Radio Liberty, Washington DC 20036