298 people were killed when the plane crashed in July 2014
A team of international investigators say the missile that brought down Malaysia Airlines Flight 17 over Ukraine in 2014 was from a 'Russian brigade'.
Experts have been analysing video images as they work to figure out what happened on July 17th 2014.
The passenger jet was headed from Amsterdam to Kuala Lumpur when it crashed, killing all 298 people on board.
Investigators had previously concluded that the plane was shot down from the ground - by a Buk missile moved into Ukraine from Russia.
Today, the investigation team - which is based in the Netherlands - detailed its latest interim report.
The team concluded: "The [Joint Investigation Team] is convinced that the BUK TELAR that was used to down MH17, originates from the 53rd Anti Aircraft Missile brigade... a unit of the Russian army from Kursk in the Russian Federation. The JIT reached this conclusion after extensive comparative research.
"The JIT presumes that within the 53rd brigade and within the circle around it, people have knowledge about the operation in which that particular BUK TELAR was deployed and about the persons that were involved in it."
Wilbert Paulissen of the Dutch National Police told a press conference: "All the vehicles in a convoy carrying the missile were part of the Russian armed forces".
Russia has denied involvement in the downing of the jet.
Chief public prosecutor from the National Public Prosecution Service, Fred Westerbeke, has said the investigation has focused on around 100 people who they believe were in some way 'associated' with the downing of the plane.
However, he explained: "It can damage the investigation and the ultimate legal procedure if we make it clear to those responsible for this event – and those further involved – how much we know exactly.
"Therefore you will understand that the courtroom pre-eminently is the place where the Public Prosecution Service speaks out about the accusation of – and the burden of proof against – individual persons."
Anybody suspected of being involved in shooting down the plane will be prosecuted in a Dutch court, following Russia blocked attempts to set up an international tribunal over the MH17 incident.
The investigation continues, although officials say 'substantial progress' has now been made towards the final conclusions.
However, they are continuing to appeal for witnesses who may have any knowledge about the incident.