A Dutch TV channel has provided what it calls “definitive proof” that Malaysia Airlines flight MH17 was shot down by a Russian-made Buk missile system. Using expert analysis of the aircraft remains and fragments of the missile that hit the aircraft, RTL News has come to its conclusion ahead of an official announcement from investigators in October.

“There is physical evidence that it was a Buk missile that brought down MH17,” the news site said Thursday. “Experts from Germany, England and Poland commissioned by RTL News viewed fragments from the wreckage and say that this is part of the Russian Buk missile.”

According to the analysis, fragments of metal from the crash, some with Cyrillic writing on them, were found to be similar to metal used inside Buk missiles. Also, impact areas were shown that are consistent with the way a Buk missile system works. The missile, which likely had a proximity fuse attached, would have exploded just moments before hitting the aircraft, releasing thousands of metal fragments into the side of the plane and causing it to fall apart in mid-air. 

MH17 was brought down over the contested region of Donbas in East Ukraine on July 17 last year while it was en route from Amsterdam to Kuala Lampur, Malaysia. All 298 passengers and crew onboard perished in the crash. But because of the war in the area between pro-Russian rebels and the Ukrainian military, investigators from the Netherlands, where 193 of the passengers were from, were unable to reach the crash site. By the time the site was clear to visit, many of the bodies had decomposed and the crash site had been tampered with.

Investigators responding to RTL’s story said that criminal investigators are still looking into the possibility that a Buk fired from the ground was responsible, but they're also entertaining the possibility that the aircraft was shot down by another aircraft.

The investigation is being carried out by what’s known as an Joint Investigation Team (JIT), which brings together experts from the Netherlands, Belgium, Ukraine, Australia and Malaysia. The research focuses on finding out the cause of the plane crash as well as finding out who is responsible.