A Ukrainian court has placed billionaire businessman Ihor Kolomoisky under arrest for two months over fraud and money laundering charges as part of the war-torn country’s crackdown on corruption, according to Al Jazeera 

The court on Saturday gave Kolomoisky the option of posting bail of more than 509 million hryvnias, equivalent to more than $13m.

In an oblique reference to legal proceedings against the business magnate, President Volodymyr Zelenskyy on Saturday thanked law enforcement bodies for bringing long-running cases to justice.

“I thank Ukrainian law enforcement officials for their resolve in bringing to a just outcome each and every one of the cases that have been hindered for decades,” Zelenskyy said in his nightly video address.

Al Jazeera Rob McBride, reporting from Kyiv, said the court’s decision has caught many people by surprise.

“This has come as a big shock here in Kyiv. There’s been rumblings of it on social media all day. Kolomoisky is one of Ukraine’s most high-profile, richest oligarchs in the country. He was a supporter of Volodymyr Zelenskyy’s presidential bid back in 2019. He has been under US sanctions since 2021,” McBride said.

“This comes amid a campaign by the Ukrainian government to tackle corruption and to be seen to be tackling corruption. There is a prevailing mood in the country at the moment that the government is tackling corruption. A number of officials have been dismissed and also been prosecuted,” he added.

Oligarchs who amassed huge fortunes

Early on Saturday, Ukraine’s main security agency, the Security Service of Ukraine (SBU), named Kolomoisky as a suspect in a criminal investigation.

“It was established that during 2013-2020, Ihor Kolomoisky legalised more than half a billion hryvnias [$14m] by withdrawing them abroad and using the infrastructure of banks under [his] control,” the SBU said in a statement.

Kolomoisky, who has previously denied allegations of wrongdoing, could not be reached for comment.

The SBU published pictures on the Telegram messaging app of a group of detectives at the door of his home, Kolomoisky being served documents and signing them.

The businessman is seen as one of the class of oligarchs who amassed huge industrial wealth after the 1991 collapse of the Soviet Union and who have wielded outsize political and economic influence.

Before Russia’s invasion of Ukraine in February last year, Zelenskyy and his team tried to clip their wings with legislation requiring oligarchs to register and stay out of politics.

The war has eroded their power as lucrative industrial assets have been destroyed in the east and south, and their television channels have been broadcasting under a centralised wartime signal.

Ukraine’s crackdown on corruption

Before he won the presidency, Zelenskyy rose to prominence as a comedian and played the role of president on a show aired on a Kolomoisky-owned TV channel. He denies Kolomoisky has had any influence over his government.

During the war, Zelenskyy has been keen to stress Ukraine’s crackdown on corruption as Kyiv has applied to join the European Union. It hopes to secure tens of billions of dollars to help rebuild the country after 18 months of war that has no end in sight.

Two lawmakers – Yaroslav Zheleznyak and Iryna Gerashchenko – suggested on Telegram that the move against Kolomoisky was aimed at generating positive publicity among Ukraine’s foreign backers as well as the public at home who are tired of the war and worried about the problem of entrenched corruption.

The SBU’s announcement on Saturday is not the first wartime move involving Kolomoisky.

In November, the state took control of stakes in major strategic companies, some of which were associated with him, invoking wartime laws to help the war effort.

This year, security officials searched Kolomoisky’s home in connection with a separate investigation into embezzlement and tax evasion at the country’s two largest oil companies, which were partially owned by the businessman.

Kolomoisky is a former owner of leading Ukrainian bank PrivatBank, which was nationalised in late 2016 as part of a major cleanup of the banking system.

He has owned an array of assets in the energy, banking and other sectors, including one of Ukraine’s most influential television channels.

The United States imposed sanctions on Kolomoisky in 2021 “due to his involvement in significant corruption”. US authorities have also alleged Kolomoisky and a business partner laundered stolen funds through the US. Kolomoisky has denied any wrongdoing.