Leading economists such as Joseph Stiglitz from the USA and Thomas Piketty from France have called on the G20 countries to create a global register of hidden wealth.
In an open letter in the British newspaper "Guardian" on Tuesday, they wrote that given the progress made in recent years in uncovering tax evasion and money laundering, for example, it was "time for a global asset register".
The letter is signed by members of the Independent Commission for the Reform of World Tax Laws, a think tank.
With a view to Russia and the Ukraine war, the open letter states that Russian oligarchs are estimated to have "at least one trillion dollars" stashed away abroad, "often hidden in foreign companies whose real owners are difficult to identify".
States are faced with a “wall of opacity”.
The signers of the letter complained that the efforts of the states that were taking action against it were currently faltering.
The Russian war of aggression in Ukraine made the “worrying situation” even worse.
At the moment, however, there is a "unique opportunity" to make progress in building an asset register, breaking up the web of shell companies and attributing assets to their true owners.
The finance ministers of the G20 meet on Wednesday on the sidelines of the spring meeting of the World Bank and the International Monetary Fund (IMF) in Washington.
It is expected that representatives of Russia will also participate in some of the sessions of the G20 meeting via video conference.
US Secretary Janet Yellen wants to stay away from these meetings in this case.
Representatives of other industrial nations are also apparently considering a boycott of the meetings with Russian representatives.