you re smart enough that money is invested in a very posh property in london. reporter: the documents also reveal the role of a major western accounting firm, pwc. in helping one of russia s wealthiest men. administer offshore companies as he grew his business empire. alexei mordashov, who was sanctioned by the eu in february, says he has always conducted his activities strictly following russian and international laws pwc told us the firm is in the process of exiting relationships with sanctioned individuals and the work it performs is in line with laws and regulations. it s absolutely complicated and good luck to regulators and authorities who are looking to this because according to some people it s already too late. reporter: now europe announced a new embargo on russian oil, but not gas, and it won t start for months the west s economic ties with russia hard to break lester keir simmons, thank you.