A Russian state-controlled missile-maker says its own investigation of last year's crash of the MH17 airliner over rebel eastern Ukraine contradicts conclusions from a Dutch probe.

Results of the Dutch investigation are to be released later today.

Yan Novikov, head of the Russian Almaz-Antey concern, speaking at a news conference, did not specify what was in the report and he did not say whether he had been given an advance look.

The Malaysian airliner crashed on July 17, 2014 in rebel-controlled eastern Ukraine and is widely believed to have been shot down by a surface-to-air missile.

Ukraine and Western countries contend the missile was fired by Russian troops or Russian-backed separatists.