The British government has also sent experts to Kiev, the Kiev Post reported.
U.S. Ambassador Geoffrey Pyatt said Monday a team from the FBI and the departments of Justice and Treasury "are working with their Ukrainian counterparts to support the Ukrainian investigation ... to uncover the financial crimes that were committed by the previous regime and to see what can be done to recoup some of those assets."
The United States, European Union, Switzerland and several other countries have frozen the assets of Yanukovych and more than 30 of his allies, including his two sons, the Post said.
Yanukovych fled Kiev in late February and is believed to be in Russia. The new government says he stole at least $70 billion.
Ukrainian journalists were able to recover thousands of pages of documents his staff had tried to burn at his estate outside Kiev.