Foreign Affairs Minister Charlie Flanagan has welcomed interim results of a criminal investigation into the downing of flight MH17.

An international investigation has concluded Malaysia Airlines flight MH17 was definitely shot down from the ground - by a Buk missile moved into Ukraine from Russia.

Head of the Dutch police investigation, Wilbert Pualissen said: "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."

He added that after the plane had been hit, the missile launcher "was taken back to Russia".

Investigators said the missile was fired from the village of Pervomaysk.

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

The report, from a team of international prosecutors, said it was unclear whether soldiers had been ordered to fire the missile, or had acted independently.

Any possibility that MH17 was brought down by another aircraft has been ruled out. The team said it had found 100 persons of interest, but individual suspects had not been formally identified.

In this file photo, Malaysian investigators along with members of the OSCE mission in Ukraine, examine a piece of the crashed Malaysia Airlines Flight 17 in the village of Petropavlivka | Image: Dmitry Lovetsky / AP/Press Association Images

However, an investigator said there was a "realistic chance" the culprits would be prosecuted.

Following the publication of the report, Minister Flanagan said: "I welcome the publication today of the initial findings of the criminal investigation into the downing of flight MH17.

"I want to acknowledge the work done by the Joint Investigation Team led by the Netherlands, comprising investigation authorities from the Netherlands, Ukraine, Malaysia, Australia and Belgium.

"Ireland has been fully supportive of the criminal investigation being undertaken by the Joint Investigation Team and today's report is part of an ongoing process which seeks to obtain justice for those who died and some closure for their families.

"I encourage all states to cooperate fully with the criminal investigation and with all efforts to establish accountability, in line with UN Security Council Resolution 2166.

"Our thoughts and sympathies remain with the families and friends of those who so tragically lost their lives. I know that today must be a particularly difficult day for them.

"We are thinking today particularly of Irish-born Edel Mahady, who was on board that fateful flight, and of her family."

Russia and Ukraine clash

Russia disagreed with the findings. Kremlin spokesman Dmitry Peskov said: "First-hand radar data identified all flying objects which could have been launched or were in the air over the territory controlled by rebels at that moment."

"The data are clear-cut...there is no rocket. If there was a rocket, it could only have been fired from elsewhere."

The investigation team said it had not gained access to new Russian radar images.

One of the investigators declined to comment on possible Russian involvement.

Moscow has suggested that the plane was brought down by the Ukrainian military.

But in a statement, the Ukrainian foreign ministry said the new findings should put an end to alleged attempts by Russia to discredit investigators' work by using "fabricated" information.

It added that the investigation was "more proof" of Russia's "direct complicity" in the downing of the airliner.

Two hundred witnesses were interviewed, and half a million videos and photographs viewed. Some 150,000 intercepted phone calls were listened to.

The investigation team was drawn from the Netherlands, Australia, Belgium, Malaysia and Ukraine.

Last year, another investigation by the Dutch Safety Board also found the plane was hit by a Buk surface to air missile, a type only made by state-controlled Russian firm Almaz-Antey.

The weapons company said the model was an old one and was no longer used by Russia.

The board did not touch on which side was likely to be responsible for launching the missile but many, including Ukrainian officials and the West, blame Russian fighters and Russian president Vladimir Putin.

In May last year, families of 33 of the victims from Australia, Malaysia and New Zealand, launched legal action against the Russian Federation and Mr Putin.

The incident also played a major part in the imposition of European Union and US sanctions on Russia over the conflict in Ukraine.

The Boeing 777 was hit during a flight between Amsterdam and Kuala Lumpur on July 17th 2014, killing all 298 people on board, most of them Dutch citizens.

The aircraft fell apart in mid air, spreading wreckage over several miles of rebel-held Ukraine.