Interpol has launched a hunt for a powerful Kremlin insider turned critic who was once known as "Putin's banker" but more recently ran into bankruptcy and fled the country.

Russian authorities accuse Sergei Pugachyov of stealing state money issued to support his now-defunct Mezhprombank during the 2008-2009 global financial crisis.

The charges come with Russia's economic fortunes on the decline and growing infighting among immensely powerful but secretive members of President Vladimir Putin's inner circle of oligarchs and security service officers.

Pugachyov was once viewed as a leader of a hawkish Kremlin clan that allegedly was responsible for the arrest and jailing of former oil tycoon Mikhail Khodorkovsky a decade ago.

The 51-year-old was until June also the majority owner of the French luxury food chain Hediard.

But he recently left Russia for an undisclosed location and has since been one of the most vocal critics of Putin and his new band of rich confidants.

Pugachyov told the Financial Times in October that "today in Russia there is no private property. There are only serfs who belong to Putin."

"Big business cannot live as before. It has to live under military rules," he added.

The comments marked a sharp contrast to charges from critics that Pugachyov was one of the instigators of a nationalization campaign launched shortly after Putin -- a former spy who openly celebrates Russia's Soviet heritage -- first became president in 2000.

Pugachyov was thought to be behind the arrest of Khodorkovsky and the transfer of his Yakos oil company's most prized assets to the once-struggling state firm Rosneft.

Interpol's official website states that Pugachyov is "wanted by the judicial authorities of Russia for prosecution".

Various countries have different rules about how to proceed should they locate a person wanted by Interpol.

Pugachyov's appearance on the agency's "red notice" list means that some European countries must either detain him pending a domestic court case or book him and release him on bail.

Countries such as Britain -- home to dozens of Russian business barons and their families -- has repeatedly refused to extradite tycoons wanted by the Kremlin because their cases seem to be launched on political grounds.

Pugachyov's lawyer said his client considered Russia's extradition request "illegal" and had no intention of turning himself in.

"He is not going to surrender to Interpol," Alexander Gofshtein told AFP. "We will fight this decision."

Pugachyov's business empire once stretched from banking to shipping and even ownership of the venerable Sukhoi jet construction bureau.

Russian state television on Thursday estimated his family's wealth at $12 billion before the 2008 crisis hit.

His status as senator representing the remote Siberian region of Tuva also guaranteed him immunity from prosecution between 2001 and 2011.

It remains unclear why Pugachyov was pushed out of Putin's inner circle after a friendship that reportedly stretched back to the early 1990s -- an era when the future Russian leader was still climbing the political ladder in his native Saint Petersburg.

But his attack on Putin comes at a time of growing infighting among the Russian business elite that some analysts attribute to the country's fast-deteriorating economic fortunes.

Western sanctions over Putin's approach to Ukraine and the sharp decline in the price of Russia's oil and gas exports -- responsible for half the country's budget revenues -- have cut Moscow's access to capital markets and seen the value of giant companies implode.

Indebted firms such as Rosneft are now pleading with Putin to approve massive bailout packages and also wrangling for ownership of lucrative assets owned by their rivals.

These battles have most recently seen Vladimir Yevtushenkov -- once Russia's 15th richest man -- placed under house arrest and stripped of his majority stake in the Bashneft oil company.

A Moscow court ruled that Bashneft was "improperly privatized" before being purchased by Yevtushenkov's holding in 2009.

But many economists think that Yevtushenkov was stripped of Bashneft because it had been targeted for acquisition by Rosneft -- a company run by close Putin ally Igor Sechin.