The airliner was brought down in eastern Ukraine last Thursday. Alexander Khodakovsky, commander of the Vostok Battalion, said that the rebels did possess the BUK missile system.
He also indicated that the BUK may have originated in Russia and could have been sent back to remove proof of its presence.
The airliner crashed with all 298 people on board. The most debated, discussed issue has been who fired the missile that brought the jet down in an area where government forces are fighting pro-Russian rebels.
Khodakovsky said the Kiev authorities started what may have been the missile strike that destroyed the airliner, saying Kiev had deliberately launched air strikes in the area, knowing the missiles were in place.