As reported by Censor.NET, this was said by Chairman of the Security Service of Ukraine Vasyl Hrytsak in an interview to 112 Ukraine TV channel.
Asked whether SBU maintained contacts with the Russian special services, he said: "We do not communicate with each other. I have never talked to the leadership of the Russian special services during my tenure."
He said members of the Russian security organizations had made themselves at home in Ukraine before the Revolution of Dignity.
"I cannot guarantee that we have got rid of all Russian agents in the SBU, but we are doing our best. We charged colonels, lieutenant colonels of the Security Service with spying for Russia. I am talking about the deputy chief of the Donetsk Directorate's Investigation Department. He is said to have been killed by explosion in downtown Donetsk last week.
"We detained him, undertook necessary investigative procedures with him, and swapped for our patriots. Unfortunately, the deputy chief of the Kyiv Counterintelligence Directorate was also working for the enemy," the SBU chief said.