Sergei Pugachev, a tycoon once dubbed "Putin's banker", has filed a claim against Russia for $12 billion after his business empire was carved up when he fell out of favour with President Vladimir Putin, his lawyers said. "Over the past few years, Russia has pursued a multi-pronged attack against me, my family, and my investments," Pugachev said in a written statement. "I refuse to be intimidated by Russia's tactics." Pugachev's notice of arbitration was delivered to Putin and Russia's ministers of economy, finance, justice and foreign affairs, his lawyers said in a statement. Reuters reported on Monday that lawyers for Pugachev had issued notice of a claim against Russia that is likely to be heard in the Permanent Court of Arbitration in The Hague.