A 'James Bond villain' oligarch who is said to keep sharks in his office to intimidate his enemies has had his mansion raided in Ukraine as part of a sweeping anti-corruption clampdown.

Ihor Kolomoisky, a warlord who helped Volodymyr Zelensky's rise to power, was targeted by the SBU, Ukraine's security service yesterday.

The 59-year-old tycoon was pictured standing in his hunting lodge residence near Dnipro wearing tracksuits and slippers as he was confronted by the agents.

Investigators are probing claims Kolomoisky embezzled around £1billion from two oil companies where he was previously the majority shareholder, Ukrainian media says.

The Ukrainian government seized stakes in the energy companies, oil producer Ukrnafta and refiner Ukrtatnafta, as part of moves to consolidate the war effort. 

The oil baron, who was named in the Panama Papers, is accused of dodging customs duties to rack up his huge fortune, which included owning the TV channel that launched Zelensky's comedy career. 

He backed the then-actor during his 2019 presidential bid with his media empire, although Zelensky has distanced himself from the billionaire businessman.

The mogul, who has been sanctioned by the US, also 'laundered $5.5billion through a tangle of shell companies, purchasing factories and commercial properties across the U.S. heartland,' the International Consortium of Investigative Journalists claims.

He is accused of heading up one of the biggest ever Ponzi schemes in the US and is one of the biggest real estate landlords in the US midwest.

Kolomoisky was born into a Jewish family in Dnipropetrovsk, Ukraine, when it was part of the Soviet Union.

After the collapse of the USSR, he started making a fortune importing foreign goods, and trading local metals on the international market.

He allegedly seized former state-held assets and paid off judges and magistrates as Russia struggled to control its burgeoning kleptocracy.

The ruthless leader soon started to cultivate a fearsome persona.

According to Forbes, he once deployed 'hundreds of hired rowdies armed with baseball bats, iron bars, gas and rubber bullet pistols and chainsaws' to forcibly take over a steel plant. 

He once lined the lobby of an oil company he wanted to push out with a row of coffins, and filled his shark tank with bloodied chum when he wanted to intimidate opponents. 

He was one of the most powerful figures in Ukraine by the 2010s and oversaw one of the country's biggest banks PrivatBank.

Following the 2014 EuroMaidan Revolution when Russia first started trying to seize Ukraine, Kolomoisky started to bankroll the neo-Nazi Azov regiment and refashioned himself as a fierce defender of the motherland.

A US diplomat said, according to the Spectator: 'I think Kolomoisky is super-dangerous. He was one of the first oligarchs who began to act like a warlord.'

But doubts crept in about the reality of his finances and government officials found billions missing from his empire.

The government was forced to give a mammoth £4.5billion bailout to PrivatBank to stop it collapsing, and soon found money hidden in faraway places such as Cleveland, Ohio. 

Investigators say he oversaw a laundering scheme that stole billions from unknowing Ukrainian depositors.

Loans that were publicly stated by PrivatBank were actually being redirected to to overseas entities using shell companies and offshore accounts.  

Kolomoisky vowed that he would turn around the fortunes of the steel heartlands of the US Midwest, but predictably it never happened, instead using the unsuspecting regions as the ideal place to hide his fortune. 

Despite his history of corruption, he remained largely untouched by the government until recently, because of his power and his influence over the militia. 

But now, authorities have clamped down on him as part of Zelensky's widening probe into corruption.

The search came ahead of a key summit with the EU and appeared to be part of a push by Kyiv to reassure key military and financial donors in European capitals and Washington that Ukraine is tackling systemic graft.

'We are carrying out the task set by Ukrainian President Volodymyr Zelensky and simultaneously delivering a global blow to the internal enemy,' announced Vasyl Maliuk, the head of Ukraine's security service, the SBU.

'Every criminal who has the audacity to harm Ukraine, especially in the conditions of war, must clearly understand that we will put handcuffs on him.'

The raids also targeted former interior minister Arsen Avakov, said the head of Zelensky's party David Arakhamia.

Law enforcement also raided tax offices in the capital and senior customs officials were fired, Arakhamia said.

In the biggest political shakeup since the launch of Moscow's assault on Ukraine, authorities last week fired around a dozen senior figures, including defence officials and a top aide to the president's office.

The raids on Wednesday came two days before Zelensky was expected to host a summit with the European Union, which has urged reforms to facilitate deeper integration.

The SBU also said it had uncovered a scheme by the head of the Kyiv tax office over 'multimillion-dollar' fraud schemes, accusing the official of abusing a position of authority.

In an address to the nation on Tuesday, Zelensky vowed officials would take further measures to sweep away graft, saying 'all the necessary steps have already been taken.'

'People in the government who do not meet the basic requirements of the state and society should not occupy their seats,' he said.

The State Bureau of Investigation and the Prosecutor General's Office said on Wednesday that they had informed a number of senior officials they were being investigated for crimes including misappropriation of state funds and misuse of state property.

Last week the defence ministry announced the resignation of deputy minister Vyacheslav Shapovalov, who was involved in logistical support for the army.

That resignation came after the ministry was accused of signing food contracts at prices two to three times higher that market rates for basics.

Despite being vocal about fighting corruption, Zelensky himself has been embroiled in corruption scandals in the past.

He is now working to drum up political backing for Ukraine at a critical time in the conflict, with Russian forces claiming to have captured fresh ground in the eastern Donetsk region.