Preliminary findings say it was hit by "high-energy objects from outside the aircraft", fuelling speculation that a surface-to-air missile was responsible.

The West and Ukraine say Russian-backed rebels brought down the Boeing 777. But Russia claims the missile was fired from Ukrainian-controlled territory.

The report will not apportion blame.

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 is first presenting its findings first to the victims' relatives and then to reporters at the Gilze-Rijen military base in the Netherlands.

The board will also show parts of the aircraft that have been brought back from the rebel-held Donetsk region and reconstructed.

The report will look at four key issues:

what caused the plane to disintegrate in mid-air

why it was flying over the conflict region

why some relatives had to wait four days before receiving official confirmation that their loved ones were on board

to what extent passengers and crew were aware of what was happening in the final moments.

However, 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.

Did they suffer? Anna Holligan, BBC News, The Hague

The Dutch Safety Board might not provide a conclusive answer as to whether the crew and passengers were conscious in those final moments.

But the families hope this technical aviation report will at least end the speculation about what caused their deaths.

"Now, finally, we're getting answers from an organisation that can verify what actually happened," says Evert Van Zijtveld - deputy chairman of the MH17 Air Disaster Association, who lost his son, daughter and parents-in-law on flight MH17.

"But we still need proof. If they say our families felt something, we want evidence."

Prosecutors have 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.

On Tuesday, Russian officials from Almaz-Antey - the state firm which manufactures Buk missiles - once again rejected those accusations.

Report 'wrong'

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 "counter-productive".

Courtesy BBC