Belgian court bailiffs notified dozens of companies and nongovernmental organizations on June 17 that the government was freezing any Russian state assets in their possession, as well as any debts they may owe to the Russian government.
Bailiffs said the seizure is based on a July 2014 decision by an arbitration court in The Hague awarding 1.6 billion euros ($1.8 billion) to Isle of Man-based Yukos Universal Limited.
Russian diplomatic missions in Belgium are exempted from the order, which was distributed to almost all major banks registered in the country, as well as to Russian media outlets and representative missions not protected by diplomatic immunity.
Bailiffs have given these entities 15 days to report any Russian government assets they have in their possession.
Russia has faced legal challenges from shareholders in the United States and European courts related to Yukos, whose former owner, Mikhail Khodorkovsky, spent a decade in prison due to prosecutions widely seen as politically motivated.
The company was dismantled following Khodorkovsky's 2003 arrest on fraud and tax-evasion charges. Russian courts subsequently seized and sold off Yukos's assets, most of which ended up in the hands of Russian state oil giant Rosneft.
In July 2014, an international arbitration court in The Hague ordered Russia to pay about $50 billion to former Yukos shareholders, ruling that Russia violated the 1991 international Energy Charter when it shut down the company and auctioned off its main assets in 2004.
Khodorkovsky, who was pardoned by Russian President Vladimir Putin in December 2013, has publicly accused the Kremlin of engineering his arrest and Yukos's downfall.
During his current self-exile in Switzerland, he has advocated for bringing an end to Putin's longtime rule through nonviolent, democratic means.