Alexander Khodakovsky, a high-ranking Ukrainian leader of Vostok battalion had confirmed the existence of a Buk missile system controlled by separatist rebels.
Khodakovsky said that the Buk may have come from Russia.
"I'm not going to say Russia gave these things or didn't give them. Russia could have offered this Buk under some entirely local initiative. I want a Buk, and if someone offered me one, I wouldn't turn it down. But I wouldn't use it against something that did not threaten me. I would use it only in circumstances when there was an air attack on my positions, to protect people's lives," Khodakovsky said.
He also said that the Buk may have been sent back to Russia to hide proof that such missile exists.
"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 was quoted saying in an exclusive interview with Reuters.
The Buk system might have also been captured by the rebels from Ukrainian bases.
However, Khodakovsky contradicted himself when he was interviewed by Russian news agencies. He said that he was talking about "possible versions" very similar to the Buk. On various local reports, he emphasised that rebels "do not have and have never had" a Buk, The Guardian reports.
Nevertheless, he condemned Ukrainian officers for letting civilian jets pass through the conflicted airspace.
"The question is this: Ukraine received timely evidence 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," Khodakovsky said.
There had been photos and videos emerging showing that the crash site of MH17 had a Buk, but leaders had denied it time and again.
If Buk indeed exist, the search for the missile and tracking down the location from where it was fired will take long, The Telegraph reports.
This is in spite of photos from the United States that showed an SA-11 missile was fired from a Buk mobile rocket launcher.
The photos from US put forward the possibility that Buk missile launchers were situated in Snizhnoye and Torez - locations nearest to the crash site - minutes before the MH17 crashed.
Highly regarded video and photo analysts, as well as bloggers, interviewed by The Telegraph were one in saying that Buk systems were being moved around the crash site of the MH17 as suggested by the photos and videos that have emerged.
"I'm satisfied they show the locations I've pin pointed them too. It does seem there's a sequence of videos and photographs from various sources showing the Buk launcher travelling through the area, which seem to make sense chronologically," Eliot Higgins of Brown Moses and Bellingcat told The Telegraph.
The purported locations around MH17's crash site, where Buk systems were reportedly being operated, is heavy with military presence as proven by vehicles tracks left along the dirt roads, The Telegraph saw in its own visit to the site.
The Telegraph found that, indeed, the area "makes a very good match for a potential launch site" even with no signs of rocket launch were visible.