For the first time, the Dutch-led team said the missile had come from a unit based in western Russia.
All 298 people on board the Boeing 777 died when it broke apart in mid-air flying from Amsterdam to Kuala Lumpur.
It was hit by a missile fired from rebel-held territory in Ukraine. Russia says none of its weapons was used.
But on Thursday Wilbert Paulissen, a Dutch official from the Joint Investigation Team (JIT), told reporters: “All the vehicles in a convoy carrying the missile were part of the Russian armed forces.”
He restated the JIT’s conclusion that the plane had been destroyed by a Russian-made Buk missile, adding that it had been supplied by the country’s 53rd anti-aircraft brigade in Kursk.
At a news conference in the Dutch city of Utrecht, the investigators also showed social media pictures which they said traced the route the missile convoy had taken to reach eastern Ukraine.
What happened to MH17?
The incident occurred at the height of the conflict between government troops and pro-Russian separatists.
The plane left Amsterdam’s Schiphol Airport on 17 July 2014 and was due to arrive at Kuala Lumpur in Malaysia…