Ihor Kolomoisky attends a court hearing at Shevchenkivskyi District Court in Kyiv on September 2. Sergei Chuzavkov/AFP/Getty Images

 A Kyiv court on Saturday ordered Ihor Kolomoisky, a Ukrainian oligarch and key supporter of President Volodymyr Zelensky, to 60 days in pre-trial detention while authorities investigate fraud charges against him, according to Ukrainian state media outlet Ukrinform.

The Shevchenkivskyi District Court ordered that Kolomoisky be held until October 31, according to Ukrinform. Kolomoisky was also given the option to post bail in excess of 500 million Ukrainian hryvnia (approximately $14 million), state media reported.

In order to post bail, he would be required not to leave the area he is staying, to appear for any interrogations and to notify authorities if he changes residences, Ukrinfrom reported. He also must surrender passports for traveling abroad, and is prohibited from contacting other witnesses or suspects involved in the investigation.

Who is Kolomoisky? Kolomoisky is a prominent Ukrainian businessman whose interests in media and banking have made him one of the country's richest men.

This is not the first time he has been accused of wrongdoing. He was sanctioned by the US State Department in March 2021 for his alleged involvement in “corrupt acts that undermined rule of law and the Ukrainian public’s faith in their government’s democratic institutions and public processes, including using his political influence and official power for his personal benefit.”

Kolomoisky was served a notice of suspicion in the ongoing case Friday.

How this connects to the war in Ukraine: While primarily occupied with fighting Russia’s invading forces, Ukraine’s government has also been cracking down on internal corruption, an issue which had been one of Zelensky’s key electoral pledges.

Tackling corruption is key for Ukraine’s ambition to join the European Union in the future. Ukraine officially became an EU candidate state last year, but Brussels has made it clear that Kyiv will need to step up its fight against corruption if it wants to become a full member.

The same goes for the NATO military alliance, with US President Joe Biden saying earlier this year that Kyiv still needs to address various governance issues, including persistent corruption, in order to join the pact.

Beyond the current conflict with Russia, Ukraine and its Western allies have said that EU and NATO membership would play key roles in protecting it against further incursions by Moscow in the long-term.