On May 11, 2026, the HACC Appeals Chamber re-examined former director of Optymumspetsdetal LLC Vitalii Zhukov as a witness in the case of Serhii Filonenko, former director of the Izium Instrument-Making Plant, who was acquitted at first instance of accepting a bribe.
Zhukov testified that he has known Filonenko for about ten years but currently has no contact with him. Their cooperation began in 2013–2014, when Filonenko headed the Izium Instrument-Making Plant and Optymumspetsdetal supplied components — including scarce electro-optical converters. Zhukov stated that contract performance involved difficulties and delivery delays, requiring the use of "any means available" to meet obligations to the plant. He confirmed that he personally never handed money to Filonenko.
During cross-examination by the defense, Zhukov clarified that meetings involving the transfer of funds to the plant's chief engineer or technologist took place one-on-one, without third parties present.
On Optymumspetsdetal's operations, he stressed that the company had a genuine capacity to supply scarce products to the defense sector and that relations between the parties were purely commercial. Logistics, mail, and delivery were coordinated by his business partner Andrii Rohoza. Zhukov noted that law enforcement had not confirmed the transactions were fictitious, and he could not recall any complaints about the quality or existence of the goods.
Particular attention was paid to Zhukov's plea agreement. When the defense asked whether he was obligated under it to give incriminating testimony against Filonenko specifically, Zhukov replied that he had committed to giving such testimony in all cases, regardless of who the defendants were.
In 2024, HACC acquitted Filonenko of accepting a bribe of over UAH 2.44 million from Optymumspetsdetal's then-director Vitalii Zhukov. The case concerns events of 2016–2017. According to the investigation, Filonenko was to conceal fraud in payments for the supply of military goods in favor of that company. Zhukov himself had previously been discharged from liability by the HACC due to the expiration of the statute of limitations.
Zhukov and Rohoza had entered a plea agreement in 2023 in a separate case concerning the supply of components for military equipment to Ukroboronprom enterprises at inflated prices. Both had also been examined as witnesses in the Filonenko case at first instance — however, the trial court questioned the reliability of their testimony, finding it likely conditioned by their plea agreement obligations.
