An investigation into Malaysia Airlines Flight MH17 has concluded that the aircraft was downed by a BUK missile fired from Russian-backed, separatist-controlled territory in eastern Ukraine.

The Joint Investigation Team (JIT) conducted an operation to identify the suspects involved in the crash that occurred on 17 July 2014.

The investigation confirmed that the 9M38 series BUK missile was used to shoot down the Malaysian plane.

During the investigation, the JIT compared parts of the alleged weapon that were found at the crash site with reference materials.

It reported that a BUK missile launcher was transported from Russia to a launch site, and returned to the country after being used to shoot down MH17, according to a statement posted on the US Department of State's website.

"A BUK missile launcher was transported from Russia to a launch site, and returned to the country after being used to shoot down MH17."

In addition, the latest radar images released by the Russian Federation showed no other aeroplanes were near MH17 when the incident occurred.

JIT members carried out the operation with investigators from Australia, Belgium, Malaysia, the Netherlands and Ukraine.

The plane was downed during a flight from Amsterdam to Kuala Lumpur, killing all 283 passengers and 15 crew members.

The JIT will continue its investigation under an agreement that has been extended until 1 January 2018.

The US has also committed to work with the JIT during its operation.

Image: Dutch and Australian police at the crash site of MH-17. Photo: courtesy of Ministerie van Defensie.