A Ukrainian official alleged Tuesday that a Russian officer deliberately pulled the trigger on a missile that took down the Malaysia Airlines passenger plane last week in eastern Ukraine.

Ukraine’s director of informational security, Vitaly Nayda, told CNN he believed it was a “Russian-trained, well-equipped, well-educated officer” who “pushed that button deliberately.”

Nayda told the cable channel that Ukrainian intelligence supported that claim. He said that conversations between a Russian officer and Moscow taped by Ukraine show there was a report to the officer that a plane was coming several minutes before the missile believed to have shot down Malaysia Airlines Flight 17 was launched.

The recording of the alleged conversations has not been released, according to CNN.

Moscow has denied that it was responsible for pulling the trigger on the missile that downed the commercial jet. In the aftermath of the crash, Russian President Vladimir Putin blamed the Ukrainian government for the tragedy.