Switzerland, Austria and Liechtenstein on Friday moved to freeze assets and bank accounts of up to 20 Ukrainians including ousted president Viktor Yanukovich and his son, after Ukraine's new rulers said billions had gone missing.
The measures were announced as the crisis in Ukraine worsened, with armed men taking control of two airports in Crimea in what Ukraine's new government described as an invasion and occupation by Russian forces, although Moscow denied involvement.
The three countries did not say how much money was affected by the asset freezes. The European Union agreed to similar measures last week but they have yet to come into force.
Ukraine's new prime minister Arseny Yatseniuk on Thursday accused Yanukovich of stripping state coffers bare and said $37 billion of credits had disappeared. In the past three years $70 billion had disappeared into offshore accounts, he added.
The Swiss government ordered the freezing of the assets of 20 Ukrainians, including the fugitive president and his son Oleksander, the Swiss financial markets authority FINMA said.
Swiss authorities said the asset freeze would come into force on Friday at noon.
The prosecutor's office in Geneva said it had also launched a money laundering investigation against Yanukovich and his son.
"A penal investigation for severe money laundering is currently being conducted in Geneva against Viktor Yanukovich and his son Oleksander," a statement said.
It said prosecutor Yves Bertossa and the police had searched the office of a company owned by Oleksander Yanukovich on Thursday morning and seized some documents.
Switzerland said on Thursday it would order banks to freeze any funds in Swiss banks found to be linked to any Yanukovich funds.