Russian authorities say they are preparing to bring new charges against William Browder, the U.S.-born former employer of the late Russian anticorruption lawyer Sergei Magnitsky.
The Interior Ministry on March 5 said Browder, the founder of the Hermitage Capital investment fund, is accused of illegally purchasing $3 billion in shares in Russia's state-controlled company Gazprom.
Browder has campaigned for the prosecution of those responsible for the death of Magnitsky, who died in pretrial detention after accusing Russian officials of fraud.
"They can sort of whip themselves up into a crazy frenzy of misuse of their own justice system, but it really has no impact on our campaign," Browder told RFE/RL's Russian Service after the announcement. "They killed Sergei Magnitsky, they tortured him to death. We're going to get justice for Sergei Magnitsky. And the more of this crazy stuff they do, the more obvious it becomes that there is a criminal regime going on in Russia who are basically doing everything they can to cover up the murder, and we're not going to let them cover it up."
The announcement of the new charges against Browder came one day after a Russian court announced on March 4 that an unprecedented posthumous trial against Magnitsky for tax evasion will start on March 11.
Browder is a co-defendant in the trial and will be tried in absentia.
In the new case, Browder is alleged to have used offshore companies registered in the names of Russian nationals to purchase the Gazprom shares between 2001 and 2004. At the time, purchases of the monopoly's stock by foreigners were banned.
An Interior Ministry official, Mikhail Aleksandrov, said Browder used his illegally acquired shares to try and gain access to secret Gazprom records and influence the company's board.
"It follows from case materials that, after acquiring [Gazprom] shares from 2001 to 2004 illegally, William Browder then actively and persistently presented his own demands to Gazprom," Aleksandrov said.
Magnitsky, who worked for Browder's fund, died in 2009 after nearly a year in pretrial detention, the maximum under Russian law.
He had accused Russian officials of stealing $230 million from the state through fraudulent tax refunds.
His death has inflamed tensions between the United States and Russia.
Last year, the United States passed legislation -- known as the Magnitsky Act -- to punish officials linked to his death as well as other Russians deemed to have committed rights abuses.
In what was widely seen as an act of retaliation, Russia late last year introduced a ban on all adoptions of Russian children by U.S. citizens.
Hermitage Capital, in a press release on March 5, said it had purchased the Gazprom shares legally.
It linked the new charges against Browder to the U.S. passage of the Magnitsky Act.
Browder was expelled from Russia in 2005.
Based on reporting by Interfax, ITAR-TASS, RFE/RL's Russian Service, AFP, and AP