National Anti-corruption Bureau of Ukraine (NABU) Director Artem Sytnyk has said the NABU had not conducted unsanctioned wiretapping in the office of Deputy Prosecutor General Anzhela Stryzhevska.

"We do not engage in unauthorized wiretapping. Everything that we listen to is done with the approval of the court," Sytnyk told reporters on Tuesday, commenting on the information about the discovery of unauthorized listening special equipment in Stryzhevska's office.

Prosecutor General Spokeswoman Larysa Sarhan earlier said that on August 17 a "bug" was discovered in Stryzhevska's office. She linked this with the corruption investigation involving NABU Director Sytnyk.

"On Saturday, in the office of the deputy prosecutor general, unauthorized wiretapping equipment was found. Ukraine's SBU State Security Service agents were called in to document this. We attribute this to the fact that Stryzhevska signed the administrative protocol involving the Sytnyk investigation," Sarhan said.

She said authorization is required from the Special Anti-corruption Prosecutor's Office (SAPO) to wiretap Ukrainian prosecutors.

A criminal case was opened into the fact of the wiretapping.

"The SBU has registered a pretrial investigation on the grounds of a criminal office under Part 1 of Article 359 of Ukraine's Criminal Code," Sarhan said on Twitter on August 19.