All 298 people, including 38 Australians, were killed when the Malaysia Airlines Boeing 777 was shot down over Ukrainian territory in July last year.
Many of those who perished were Dutch and a report from the Netherlands released this week concluded that the plane was shot down with a Russian-made Buk missile.
However, the long-awaited findings of the the Dutch Safety Board, which was not empowered to address questions of responsibility, did not point the finger at any group or party for launching the missile.
A bitter war was raging in eastern Ukraine between Russian-backed separatists and Ukrainian government forces when the aircraft was downed and, amid a huge international outcry, many Western experts and governments immediately blamed the rebels.
Newstalk's Australia correspondent Donna Demaio said Mr Turnbull was acknowledging the continuing pain of the families of the 38 Australians who died.
He wanted to write to the bereaved families to assure them they have the heartfelt sympathies of the nation as the process continues.
Meanwhile, Dutch Prime Minister Mark Rutte urged Russia to cooperate fully with a separate criminal investigation the Netherlands is leading, with participation from Malaysia, Australia, Ukraine and Belgium.
Russia disputes that a Buk may have been used. Deputy Foreign Minister Sergei Ryabkov responded to the report by saying there had been "an obvious attempt to draw a biased conclusion, and carry out political orders", according to Russian news agencies.
- NEWSTALK and Reuters
