Former Federal Bureau of Investigation director William Sessions once condemned Russia's rising mafia. "We can beat organized crime," he told a Moscow security conference in 1997.

Today, Mr. Sessions is a lawyer for one of the FBI's "Most Wanted": Semyon Mogilevich, a Ukraine-born Russian whom the FBI says is one of Russia's most powerful organized-crime figures.

Mr. Sessions is trying to negotiate a deal with the U.S. Department of Justice for his client, who is charged with racketeering and is a key figure in a separate Justice Department probe of energy deals between Russia and Ukraine.

A number of notable Washington insiders are earning big fees these days by representing controversial clients from the former Soviet Union.

From prominent businessmen -- some facing criminal allegations -- to top politicians, well-known ex-Soviets are lining up to hire help with criminal cases, lobbying and consulting. These figures, many of whom made fortunes in the wide-open 1990s amid the Soviet Union's disintegration, hire Washington insiders to help rehabilitate their reputations in the West or to persuade investors and regulators they are committed to good corporate governance.