State security officials searched the home of billionaire businessman Ihor Kolomoiskiy on Wednesday as part of an investigation into possible financial crimes, several Ukrainian media outlets reported, citing an unnamed official source.

The State Security Service of Ukraine (SBU) did not immediately reply to a request for comment about the reports. Kolomoiskiy could not be reached for comment.

Kolomoiskiy is one of Ukraine’s richest men and a one-time ally of President Volodymyr Zelenskiy who launched a crackdown on wealthy businessmen known as “oligarchs” in late 2021, before Russia invaded its neighbour last year.

Kolomoiskiy, who is from the central city of Dnipro and owns an array of assets including one of Ukraine’s most influential television channels, backed Zelenskiy’s election campaign in 2019.

Ukrainska Pravda, one of at least three outlets reporting the raid on Kolomoiskiy’s home, said the move related to an investigation into the alleged embezzlement of oil products and evasion of customs duties.

The search was carried out by officials from the SBU and the Economic Security Bureau of Ukraine.