A criminal inquiry into the downing of Flight MH17 said Wednesday it is investigating 100 people for a missile attack on the plane two years ago over eastern Ukraine, saying the system used had been transported from Russia.

The investigators also confirmed that the BUK missile which slammed into the Malaysia Airlines plane was fired from a field in a part of eastern Ukraine which at the time was under the control of pro-Russia separatists.

The Boeing 777 passenger jet was brought down over rebel-held eastern Ukraine in July 2014 on a routine flight from Amsterdam to Kuala Lumpur, killing all 298 people on board including 196 Dutch citizens.

"Our investigation has shown that the location from where the BUK was fired was in the hands of the Russian separatists," said Wilbert Paulissen, the head of the Dutch police investigation.

The joint investigation "has identified approximately 100 people who can be linked to the downing of MH17 or the transport of the BUK-TELAR" missile system, Dutch prosecutors said.

They were believed to have had an "active role" in the transporting of the missile system used to bring down the routine flight from Amsterdam to Kuala Lumpur, chief investigator Fred Westerbeke said.

But he stressed those under investigation were not official suspects yet.

As expected the investigators did not reveal any names, but it revealed the exact missile system used.

"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," Paulissen added.

He added that afterwards the missile launcher system "was taken back to Russia."

Russia this week again sought to deflect the blame for the MH17 disaster, on Monday releasing what it said were radar images showing that no missile fired from rebel-held territory in the east could have hit the plane.

Kremlin spokesman Dmitry Peskov insisted Wednesday that Russia had provided "exhaustive information" which investigators should take into account.

"The data is unequivocal and on that data, there is no missile. Therefore if there was a missile it could have been launched only from a different territory," he said.

Ukraine and the West insist pro-Russian rebels blew the jet out of the sky with a Russian-made missile system likely supplied by Moscow.

The tragedy saw the European Union slap tougher sanctions on Russia -- blamed by the West for being behind the rebellion. The punitive measures remain in place as the fighting drags on.

But Russia and the rebels have consistently denied any role in downing the plane, and have instead blamed Ukrainian government forces.