Zaporizhia Mayor Volodymyr Buriak has been called for questioning by Ukraine's SBU State Security Service as a witness in a case on state treason and buying votes, the U.S.-government funded Radio Free Europe/Radio Liberty news portal has said, citing the press service of the SBU's office in Zaporizhia.

"We are summoning Buriak for questioning as a witness. There is a case being investigated. Buriak is not the only person to be called. There are several people, who can explain the circumstances of the affair being investigated," SBU Spokesman Serhiy Levchenko was quoted as saying.

The names of other persons summoned for questioning is not being revealed.

The SBU's press service told RFE/RL that the mayor has not been handed a summons to appear for questioning.

Meanwhile, the Batkivschyna Party's representative in Zaporizhia Vitaliy Riabtsev said on his Facebook page that in addition to Buriak Zaporizhstal Director Rostyslav Shurma, Deputy City Mayor Anatoliy Pustovarov, Zaporizhia Regional Council Deputy Viktor Busko and "other suspects in a dirty political fight" have been summoned for questioning also.