Head of the Security Service of Ukraine Vasyl Hrytsak said he did not know about the materials of the so-called shadow costs of the Party of Regions.

"Unfortunately, I didn't know anything about the preparations for the transference of the shadow costs materials to NABU," Hrytsak said at a briefing in Kyiv on Monday.

Hrytsak noted that former Deputy Head of the Security Service of Ukraine Viktor Trepak wrote a letter of resignation and is currently on vacation. "This means that formally he is an SBU employee as there is no order to dismiss him. Being an SBU officer, who knows Ukrainian legislation and norms of law well, he is aware that it would be necessary at least to report the circumstances of obtaining this information to the head of the Security Service," he said.

Hrytsak added that Trepak had to pass these materials to the SBU for legal assessment. "Unfortunately, that did not happen," Hrytsak added.