International prosecutors investigating the downing of flight MH17 over eastern Ukraine in 2014 say the missile hit the aircraft was launched from the territory controlled by rebels supported by Russia.
They said the missile launcher was brought to Ukraine from Russia.
All 298 people aboard the Boeing 777 were killed when disintegrated in the air flying from Amsterdam to Kuala Lumpur.
Relatives told the BBC that prosecutors said they would investigate about 100 people for the incident.
“They told us how the Buk was transported [and] how they came to that evidence from phone taps, photo, film material, video,” Robby Oehler, whose niece was killed in the crash, told the BBC.
Russia has disputed claims that the missile was fired by rebels in eastern Ukraine.
The Dutch-led Joint Investigation Team (JIT) consists of prosecutors from the Netherlands, Australia, Belgium, Malaysia and Ukraine.
“Based on the criminal investigation, we have concluded that flight MH17 was downed by a Buk missile of the series 9M83 that came from the territory of the Russian Federation,” chief Dutch police investigator Wilbert Paulissen said.
The missile launcher was later taken back to Russia, he said.
An inquiry by the Dutch Safety Board last year found that a Russian-made Buk missile hit the plane but did not say where it was fired from.
The JIT investigation’s findings are meant to prepare the ground for a criminal trial but suspects will not be named.
Prosecutors played recordings from intercepted phone calls during their news conference.
They said witnesses reported seeing the missile launcher move from Russia into Ukraine and presented pictures and videos.
The launch site was pinpointed by “many witnesses”, prosecutors said,
Separatist rebels have denied they were involved.
“We never had such air defence systems, nor the people who could operate them,” Eduard Basurin, military deputy operational commander at the rebel Donetsk People’s Republic, told the Interfax news agency.
“Therefore we could not have shot down the Boeing [flight MH17].”
Earlier this week, Russia said it had radar data showing that the missile was not fired from rebel-held territory.
The JIT does not yet have access to that data, prosecutors said.