Black boxes from the downed Malaysian jet show it was destroyed by shrapnel coming from a rocket blast and went down because of "massive explosive decompression", a Ukrainian security official said.
The spokesman for Ukraine's Security Council, Andriy Lysenko said the information came from experts analysing the recorders.
Experts in Britain were tasked with downloading the data from two black boxes recovered from the crash site and handing that information over to international investigators for analysis.
Kiev and the West accuse pro-Russian rebels of shooting down the plane. Moscow says the Ukrainian government is responsible for the crash, which killed all 298 people on board.
The mother of the three Australian children killed on flight MH17 told a memorial service her "arms would always be reaching for them."
A woman has apparently posted pictures of herself on social media with mascara looted from the Malaysian Airlines flight MH17 crash site.
A large section of plane wreckage and everyday carry-on items like chocolates remain scattered among the wild flowers at the crash site.