British Prime Minister David Cameron and United States President Barack Obama are facing calls to take financial action against the likes of Roman Abramovich, the Chelsea soccer club owner, over Russia's annexation of Crimea.
A prominent Russian opposition politician said Western Governments' response to the Crimean crisis should include seizingthe assets of wealthy Russian businessmen, such as Abramovich and Alisher Usmanov, a shareholder in the Arsenal club.
So far, Western sanctions imposed in protest at Russian aggression in Ukraine have fallen on Russian politicians and officials.
But Alexei Navalny, a leading critic of Russian President Vladimir Putin, said the sanctions should be aimed at billionaire "oligarchs" with close links to Putin.
Navalny said the West should take action including "freezing the oligarchs' financial assets and seizing their property".
In an article in the New York Times, he called for action against a list of businessmen including Abramovich and Usmanov.
Neither man has any public connection to Putin or the Russian Government.
Abramovich declined to comment. He is understood to consider himself a private citizen with no connection to the Russian Government, meaning there should be no question of sanctions being applied to him.
The White House yesterday imposed sanctions on at least half the names on Navalny's list - including Putin's right-hand man, Sergei Ivanov. However, neither Abramovich nor Usmanov faces any action from US authorities. Nor has Britain taken any action against them so far.
Russia, meanwhile, says it has imposed entry bans on nine US politicians and officials in retaliation to Washington's sanctions over Crimea.
The Russian Foreign Ministry released the list that includes John Boehner, the speaker of the House of Representatives and Robert Menendez, the head of the Senate Foreign Affairs Committee.
