The Russian maker of the Buk air defence missile system says it has concluded Malaysian Airlines flight 17 was downed by an older version of the missile.

It says the type is not in service with the Russian military but is in Ukrainian arsenals.

Mikhail Malyshevsky, an adviser to the director general of the state-controlled Almaz-Antei consortium, said the analysis was based on photographs of the wreckage available to the public.

Controversy continues over who shot down the plane last summer over eastern Ukraine, killing all 298 people aboard.

Ukraine and the West suspect it was destroyed by a Russian surface-to-air missile fired by Russian forces or separatist rebels fighting in the area.

Mr Malyshevsky said the holes in the plane's parts were consistent with a specific type of Buk missile and its warhead.