The National Anti-corruption Bureau of Ukraine (NABU) together with the special investigations bureau of Ukraine's Prosecutor General's Office (PGO) is continuing its investigation into the so-called 'black ledger' used by the Party of Regions.

NABU on Friday said that a year of investigating the case included handwriting expertise to establish the authenticity of signatures of several individuals, and, in December 2016, the head of Ukraine's Central Election Commission Mykhaylo Okhendovsky was served with a notice of suspicion.

"In the opinion of our agents enough evidence to serve suspicion notices, at least to one individual as a minimum, has been gathered," the NABU post said.

The head of the Specialized Anti-Corruption Prosecutor's Office (SAPO) Nazar Kholodnytsky is not obliged to receive approval from detectives to close the case against Okhendovsky. SAPO agents say evidence to send the case to court is sufficient.

"In the opinion of NABU evidence gathered by detectives is sufficient to serve Okhendovsky with a notice of suspicion in its final redaction and notify the court of a prosecutorial notice. However, according to Article 279 of Ukraine's Procedural Code, only Kholodnytsky has that right, inasmuch as he signed the first notice of suspicion," the NABU press release said.

In the context of the decision taken by SAPO to send the materials of the case to the PGO, NABU will continue working on its findings together with a joint investigatory group with the PGO's bureau of special investigations and hopes facts established by NABU will receive the appropriate legal appraisal.