Russian President Vladimir Putin yesterday dismissed his influential deputy prime minister Vladislav Surkov, who is credited with helping to shape the country's tightly controlled political system. His departure comes amid what observers describe as signs of growing infighting among Kremlin elites during Putin's controversial third term and an ongoing probe of a hi-tech fund backed by Surkov. In a statement, the Kremlin said Surkov had left his post voluntarily. Surkov declined immediate comment to reporters, but Kommersant FM radio, citing the former official, said he had tendered his resignation on April 26. Putin's spokesman said Surkov's departure should not be seen as related to the investigation of technology fund Skolkovo. Instead, he suggested that the deputy prime minister had quit because of the government's poor implementation of Putin's election promises. "Surkov has quit voluntarily … it is related to the priority topic and the high-priority task of implementing presidential decrees," Dmitry Peskov told the radio station. Surkov has quit voluntarily … it is related to the priority topic and the high-priority task of implementing presidential decrees Surkov served as deputy prime minister after being dismissed from the post of first deputy Kremlin chief of staff in a shake-up in December 2011 following huge protests that shook Russia that winter. Surkov, 48, was considered the ideologue of Putin's domestic political strategy, who oversaw political parties in parliament, electoral campaigns and the tightly muzzled media. He worked in the Kremlin administration from 1999 before his unexpected transition to the government, which was seen at the time as the Kremlin's reaction to 2011's mass anti-Putin protests. He is known for coining the term "sovereign democracy" to describe Russia's autocratic political system, and was once called the "Kremlin puppeteer" by billionaire Mikhail Prokhorov. Russian investigators are now probing Skolkovo, where Surkov sits on the supervisory board. Last month, the powerful Investigative Committee - Russia's equivalent of the American FBI - accused one of the fund's senior executives of giving US$750,000 to an opposition lawmaker. Surkov has publicly defended the fund, saying in a recent speech in London that investigators should not come to any premature conclusions.