The Russian maker of the Buk air defence missile system says it has concluded that 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.
Each of the Buk subtypes has its warhead rigged with shrapnel of a specific shape. This type of missile is in the Ukrainian military arsenals, but not in the Russian, said Almaz-Antei director Yan Novikov.
While the pair stopped short of directly blaming Ukraine for shooting down the plane, their statements hinted at that.
Mr Malyshevsky also said that the area from where the missile was likely launched was not rebel-controlled Snizhne, as Ukraine and some Western commentators had suggested, but another place controlled by the Ukrainian government.
Mr Novikov said that in 2005 when Ukraine contacted the consortium regarding the maintenance of its Buk systems, it had 991 such missiles.
Rebels have staunchly denied even possessing a functioning Buk missile launcher at the time that MH17 was brought down, although one was seen in separatist-controlled Snizhne by AP reporters a few hours before the plane crashed.
Ukrainian military spokesman Vladislav Seleznev was quoted by the Interfax news agency as saying photos and video materials at the time documented the presence of a Buk on the rebel-held territory.
A spokesman for the Dutch Safety Board, which is investigating the crash, declined to comment on the consortium's statement. The Dutch report is expected in October.