Leader of Batkivschyna faction Arseniy Yatseniuk has said that on Monday defender of Ukraine's ex-premier Yulia Tymoshenko and ex-MP Serhiy Vlasenko was arrested.

"Just now I've got an SMS sent by Serhiy Vlasenko from the prosecutor's office saying that he has been arrested," Yatseniuk said during the unscheduled sitting of the Parliamentary Committee on Legislative Support of Law Enforcement.

"Concerning reports about Serhiy Vlasenko. If this is the truth, it means the frustration of the Vilnius Summit. This is the main task set before us now," the politician said.

Interfax-Ukraine is making inquiries at the Prosecutor's General Office on this matter.