Russian President Vladimir Putin on Wednesday dismissed his influential deputy prime minister Vladislav Surkov credited with designing the country's tightly-controlled political system.

Surkov had left his post voluntarily, the Kremlin said in a statement.

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 high-tech fund backed by Surkov.

Surkov declined immediate comment to reporters but Kommersant FM radio, citing the former official, said he tendered his resignation on April 26.

Putin's spokesman said Surkov's departure should not be seen in connection with the investigation at the Skolkovo fund.

Instead, he suggested that the deputy prime minister quit because of the government's poor implementation of Putin's election promises.

"Indeed, Surkov has quit voluntarily, it is related to the priority topic and the high-priority task of implementing presidential decrees," Dmitry Peskov told the Kommersant FM radio.

Peskov told Echo of Moscow radio that he did not know what Surkov would do next.

Surkov had served as deputy prime minister after being dismissed from the post of first deputy Kremlin chief of staff in a shakeup in December 2011 following huge opposition protests that shook Russia that winter.

Surkov, 48, has been considered the ideologue of Putin's domestic political strategy who oversaw political parties in parliament, electoral campaigns and the tightly controlled media.

He worked in the Kremlin administration from 1999 before his unexpected transition to the government seen at the time as the Kremlin's reaction to the mass anti-Putin protests in 2011.

He is known for coining the term "sovereign democracy" to describe Russia's controlled political system and was once called the "Kremlin puppeteer" by billionaire Mikhail Prokhorov.

The departure of Surkov, who had for the past year and a half been in charge of modernising the Russian economy, comes as Russian investigators are probing the Skolkovo hi-tech fund where Surkov sits on the supervisory board.

Last month, the hugely powerful Investigative Committee, Russia's equivalent of the FBI in the United States, accused one of the fund's senior executives of giving $750,000 to an opposition lawmaker.

Surkov has publicly defended the fund, saying in a recent speech at the London School of Economics that investigators should not come to any premature conclusions.

In the speech on May 1, he said the Investigative Committee's press department's "artillery fire" on Skolkovo may damage the sensitive project.

"Maybe one should not speak so loudly about possible violations before a court decision," he said in televised remarks.

The speech proved largely controversial and drew a sharp rebuke from the chief spokesman of the Investigative Committee.

In an acidly-worded letter published on Tuesday on the front page of the pro-Kremlin newspaper Izvestia, the spokesman Vladimir Markin accused Surkov of criticising Russian officials from abroad.

"How long would a member of Her Majesty's Cabinet be able to hold on to his post if he, while on a private visit to Moscow, publicly condemned Scotland Yard for performing its direct duties?" Markin said.

When asked to comment on Markin's article, Surkov, known as a media-shy intellectual and art lover who himself dabbles in literature, said he would not comment on "graphomania".

Observers say the highly unusual spat between Surkov and Markin highlights increasing rifts between the powerful Kremlin elites, particularly the security hardliners and more liberal officials that have supported Prime Minister Dmitry Medvedev.

Unlike Putin's current first deputy chief of staff Vyacheslav Volodin, Surkov's career was launched in the private sector.

He once worked for the now jailed oil tycoon Mikhail Khodorkovsky, first reportedly as his bodyguard and then in his public relations department.