Security forces in Ukraine have arrested Hennadiy Korban, who ran unsuccessfully for mayor of Kyiv last month.
Officials say Korban, who is the head of the UKROP party and who is a close associate of former Dnipropetrovsk Governor and oligarch Ihor Kolomoyskiy, was arrested in Dnipropetrovsk on October 31 on suspicion of participating in an organized crime group.
UKROP issued a statement saying that the arrest and searches of the party's offices and the homes of party officials were an act of "political repression."
Korban is accused of involvement in several kidnappings when he served as deputy governor of Dnipropetrovsk in 2014-15. He is also accused of stealing about $1.7 million from a fund earmarked for Ukrainian soldiers fighting against Russia-back separatists in eastern Ukraine.
About 500 security officers were involved in the operation, and an unknown number of other arrests were also made.
Kolomoyskiy, Ukraine's second-richest man, served briefly as head of Dnipropetrovsk Oblast and was credited with preventing the spread of separatist sentiment in the region.
But President Petro Poroshenko dismissed him in 2015, accusing him of setting up a private militia and trying to take over a state-affiliated oil company.