The investigation
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MH17: Launch site 'key' to identifying who fired missile

21 July 2014 Last updated at 22:11 BST

The Malaysian prime minister, Najib Razak, says an agreement has been reached with pro-Russian separatists in control of the area where a Malaysia Airlines plane crashed to give independent international investigators access to the site.

Rebel leader, Alexander Borodai, also agreed to hand over flight recorders to a Malaysian team in Donetsk.

However US satellite data may offer the best answers to what happened to flight MH17.

Richard Westcott reports.