Who is investigating?
Observers from the Organization for Security and Co-operation in Europe (OSCE) - whose job it was to observe the site ahead of the arrival of investigators - were the first team to visit the debris zone, however their movements were restricted by militiamen.
Responsibility for the investigation belongs to the state within which an incident occurs, according to the International Civil Aviation Organization.
As such, the Ukrainian government initiated that probe, but the DSB was asked to head the main investigation, as the majority of victims were from the Netherlands.
The separate, Dutch-led JIT has been gathering evidence for a possible criminal trial.
In July 2015, Russia vetoed a draft resolution at the UN Security Council to set up an international tribunal into the disaster. President Vladimir Putin said it would be "premature" and "counter-productive".