On 1 February, the National Anticorruption Bureau of Ukraine (NABU) searched the office of the oil extraction company Ukrnafta, NABU chief Artem Sytnyk has told Ukrainian News.
"Yes, Ukrnafta was searched today," he said.
In September 2016, the NABU opened a case over a debt of almost 8bn hryvnyas (about 297m dollars) accumulated by companies affiliated with businessman Ihor Kolomoyskyy.
The state owns 50 per cent plus one share in Ukrnafta, which are managed by the state-owned oil and gas company Naftohaz Ukrayiny. The remaining shares are controlled by Kolomoyskyy's Privat Group.