"That BUK I know about. I heard about it. I think they sent it back. Because I found out about it at exactly the moment that I found out that this tragedy had taken place. They probably sent it back in order to remove proof of its presence," Khodakovsky told Reuters on Tuesday.

"The question is this: Ukraine received timely evidence that the volunteers have this technology, through the fault of Russia. It not only did nothing to protect security, but provoked the use of this type of weapon against a plane that was flying with peaceful civilians," he said.

"They knew that this BUK existed; that the BUK was heading for Snezhnoye," he said, referring to a village 10 km (six miles) west of the crash site. "They knew that it would be deployed there, and provoked the use of this BUK by starting an air strike on a target they didn’t need, that their planes hadn’t touched for a week."

"And that day, they were intensively flying, and exactly at the moment of the shooting, at the moment the civilian plane flew overhead, they launched air strikes. Even if there was a BUK, and even if the BUK was used, Ukraine did everything to ensure that a civilian aircraft was shot down."

Eileen Lainez, a Pentagon spokeswoman, said Khodakovsky's remarks confirmed what U.S. officials had long been saying, that "Russian-backed separatists have received arms, training and support from Russia."

But she dismissed the rebel leader's efforts to blame the Kiev government for the downing of the airliner, calling it "another attempt to try to muddy the water and move the focus from facts."

Washington believes that pro-Russian separatists most likely shot down the airliner "by mistake," not realizing it was a civilian passenger flight, U.S. intelligence officials said. (rt/ez)