The report said the financial transactions were enabled by the secrecy and anonymity with which the art market operates and it called for tighter rules to force greater transparency. The investigators concluded that the auction houses — including Christie’s and Sotheby’s — and private sellers never knew the true identity of the oligarchs who were buying the art, but they said that was a loophole that needs to be closed for a sanctions policy to be truly effective. – The New York Times