Malaysian Airlines Flight MH17 crashed as a result of a Russian-made 9M38 Buk missile, the Dutch Safety Board says.
The missile hit the front left of the plane, as a result of which part of the plane broke off, it said in a final report into the disaster.
The West and Ukraine say Russian-backed rebels brought down the Boeing 777. But Russia claims a missile was fired from Ukrainian-controlled territory.
The report will not apportion blame but says airspace should have been closed.
Relatives of some of the 298 people who died over Ukraine in 2014 have been told victims would have lost consciousness almost immediately.
The plane - flying from Amsterdam to Kuala Lumpur - crashed in rebel-held eastern Ukraine on 17 July 2014 at the height of the conflict between government troops and the pro-Russian separatists.
Among the victims were 196 Dutch nationals and 10 Britons.
The Dutch Safety Board presented its findings first to the victims' relatives before briefing reporters at the Gilze-Rijen military base in the Netherlands.
The board showed parts of the aircraft that have been brought back from the rebel-held Donetsk region and reconstructed.
- Barry Sweeney, father of British crash victim Liam Sweeney, earlier told the BBC that he had been told it appeared a missile had struck the cockpit first - killing all three crew inside and leaving fragments inside their bodies.He said the cockpit then appeared to have broken off.But he and other relatives briefed on the report say they were told it was extremely unlikely that anyone on board had any notion of what was happening.The board does not have the authority to apportion blame, under the rules governing international flight crash investigations.A separate Dutch-led criminal investigation is expected to publish its findings in several months' time.Dutch Safety Board president Djibbe Joustra suggested that the aircraft was most likely brought down by a Russian-made Buk surface-to-air missile - which experts say both Russian and Ukrainian armies possess.The government in Ukraine and several Western officials have said the missile was brought from Russia and launched from the rebel-held part of Ukraine.
Report 'wrong'Earlier on Tuesday, Russian officials from Almaz-Antey - the state firm which manufactures Buk missiles - once again rejected those accusations.During a presentation timed to pre-empt the Dutch report, officials said the evidence suggested the plane was shot down by a surface-to-air Buk missile fired by Ukrainian forces.
- Using video footage of their own mock-up of shrapnel hitting the fuselage of an aircraft, the officials said trajectory evidence showed the missile had been fired from Ukrainian-controlled territory. They argued the missile used was a decades-old model no longer in use in the Russian arsenal.Russia says Dutch investigators have not taken account of its findings.In July, Russia vetoed a draft resolution at the UN Security Council to set up an international tribunal into the MH17 air disaster.President Vladimir Putin said at the time the establishment of such a tribunal would be "premature" and "counterproductive".