The government said that the freeze on Russian assets in Switzerland now stands at $6.3 billion.

At a government briefing in Bern, the Swiss official said that the amount of assets frozen as of April 7 was 7.5 billion Swiss Francs ($ 7.5 billion). Even though an additional 2.2 billion Swiss Francs have been blocked since early April, 3.4 billion Swiss Francs were released again after being frozen on a precautionary basis.

The number of frozen assets is not an indicator of how effective sanctions are.

Last week, outspoken Kremlin critic Bill Browder said at a US government-sponsored briefing on Russian money in Switzerland that the US should reconsider its legal cooperation with the Swiss. Switzerland's role as a magnet for Russian wealth over the past two decades has come under scrutiny, even as it imposed sanctions that mirrored those of the European Union.

According to Mark Pieth, a law professor at the University of Basel and a corruption expert, the Swiss authorities have shown a lack of courage in dealing with Russian assets in the country.

The majority of Russian assets in Switzerland are not subject to sanctions and should not be seized. As more assets hidden behind shell companies or in the names of associated are uncovered, the number will continue to rise.