Authorities in the Netherlands are due to publish a preliminary report on the July downing of Malaysia Airlines flight MH17 over eastern Ukraine.
The Dutch Safety Board (DSB) says the report which will be published later today will include details gathered from the cockpit voice recorder, the flight data recorder, satellite and other images, and radar information.
It is not clear whether the evidence will provide any proof of who fired the missile thought to have brought down the plane, killing all 298 people aboard.
On the day of the disaster, a pro-Russia separatist leader claimed on social media that his forces had shot down a Ukrainian warplane but then removed the claim after it became clear a civilian airliner had been brought down.
The Ukrainian government has also published intercepts apparently between separatists suggesting their side fired the missile. It is unclear whether the DSB report will comment on the authenticity of those intercepts.
The US and Ukraine have accused Russian forces of launching the missile, but Moscow has denied the charge, pointing instead at the Ukrainian air force.
On its website the Dutch board said: “The DSB will not make any statements with regard to apportioning blame or liability, and these issues will not form part of its investigation.”
The report will come out hours after the expected imposition of a new wave of European oil sanctions on Russia for its role in stoking the separatist revolt in eastern Ukraine.
The sanctions were due to take effect overnight, but discussions were underway in the early evening aimed at resolving last-minute disagreements over the extent and scope of the measures.
According to sources in Brussels, the new restrictions will bar Russia's top oil producers and pipeline operators Rosneft, Transneft and Gazprom Neft from raising capital on European markets.
The sanctions will not include Russia's gas sector and in particular state-owned Gazprom, the world's biggest gas producer and the biggest gas supplier to Europe.
Because of earlier fighting around the MH17 crash site, DSB investigators have been unable to visit the scene, but the organisation said it carried out an investigation based on other sources of information.
It added: “Once a secure and stable situation has been established, the Dutch Safety Board will visit the location. This is in order to verify the results of the investigation from other sources and to conduct a specific search for wreckage and other vital pieces.”
A final report is expected to take up to a year but rules set out by the International Civil Aviation Organisation require a progress report to be issued.
“The preliminary report is not subject to any criteria in terms of structure or scope. The content is partly dependent on the progress of the investigation and the need to report certain findings,” the DSB website said, adding that the interim report would allow “an initial, provisional sequence of events to be made”.
Investigative journalism website, Bellingcat, has published photographs it said suggested that the anti-aircraft missile involved in the attack was fired by a Russian unit, the 53rd Buk brigade, based in the city of Kursk. "The new information presented in this article adds to the existing evidence that the Russian government bears responsibility for the tragedy," it said.