" For years, the suspicion that Mr. Putin has a secret fortune has intrigued scholars, industry analysts, opposition figures, journalists and intelligence agencies but defied their efforts to uncover it. Numbers are thrown around suggesting that Mr. Putin may control $40 billion or even $70 billion, in theory making him the richest head of state in world history. For all the rumors and speculation, though, there has been little if any hard evidence, and Gunvor has adamantly denied any financial ties to Mr. Putin and repeated that denial on Friday. But Mr. Obama’s response to the Ukraine crisis, while derided by critics as slow and weak, has reinvigorated a 15-year global hunt for Mr. Putin’s hidden wealth. Now, as the Obama administration prepares to announce another round of sanctions as early as Monday targeting Russians it considers part of Mr. Putin’s financial circle, it is sending a not-very-subtle message that it thinks it knows where the Russian leader has his money, and that he could ultimately be targeted directly or indirectly. “It’s something that could be done that would send a very clear signal of taking the gloves off and not just dance around it,” said Juan C. Zarate, a White House counterterrorism adviser to President George W. Bush who helped pioneer the government’s modern financial campaign techniques to choke off terrorist money. "

― Peter Baker