On an empty highway, through a gap in some trees, a truck hauling a missile launcher can be seen flashing past on the way to Russia.

The moment is captured in a grainy video, which shows two white-tipped missiles on the weapon's army-green rig and a missile-sized gap between them.

Dutch prosecutors say it's the missile launcher used to shoot down Malaysia Airlines Flight 17 and kill 298 people, including 38 who called Australia home.

Prosecutors have never revealed the identity of the person who filmed the video. Whoever it was, they surely could not have known then how significant the footage would become to a six-year criminal investigation.

The Netherlands has put Russians Igor Girkin, Sergey Dubinsky, Oleg Pulatov and Ukrainian Leonid Kharchenko on trial in absentia over the tragedy.

The four, accused of murder, were leaders of the breakaway Donetsk People's Republic during Ukraine's War in Donbass between the eastern European nation and Russian-backed rebels.

The four allegedly organised the Russian-made Buk-TELAR missile launcher; those who actually pulled the trigger are still on run, supported by an apparent campaign to mislead and obstruct the international Joint Investigation Team (JIT)at every step.

Dutch Prosecutor Thijs Berger told the District Court of the Hague last week the JIT has meticulously analysed and ruled out Kremlin-pedalled explanations for the MH17 disaster.

Suggested theories included an onboard explosion, a fighter jet attack or a missile other than a Buk.

But the JIT concluded an onboard explosion or a fighter jet attack couldn't have damaged the plane's nose, cockpit, undercarriage and fuselage in the way it was.

There were also no surface-to-air missile launchers other than Buk-TELARs in the region at the time.

And claims by sole witnesses of up to four alternate launch sites could not be substantiated by the JIT, the court heard.

In at least one case, Russia inexplicably provided investigators with doctored satellite photographs.

Perhaps the most exasperating episode for investigators was when the Kremlin suggested a Ukrainian Buk-TELAR transferred from Russia in 1986 was the weapon used to down MH17.

Military documents were provided by Vladimir Putin's government to back up the theory, but the badly faded files had fresh pen marks and were riddled with inconsistencies.

"We have to conclude that the Russian Federation did not act in good faith in this investigation," Berger said.

Russian Foreign Ministry spokeswoman Maria Zakharova maintained this week the missile used to bring down MH17 was Ukrainian.

"Nevertheless, the prosecutors claim -- they do it without evidence -- that the Russian data 'were manipulated and rigged'," Zakharova told Sputnik.

"It's a lie. Another lie. After all, they were invited to visit Russia, to see the authenticity of the logbooks with their own eyes, but the investigators somehow cooled off right away. They neither expressed their desire to come, nor sent any additional requests."

To prosecutors, it's apparent that every single alternate theory was a ploy, designed to deceive and delay the investigation.

And new evidence suggests those who fired the missile may not have been bumbling rebels as was previously believed, but soldiers trained to operate a Russian Buk-TELAR.

A witness known only as X48 told of seeing four soldiers dressed in unusual khaki uniforms and helmets with ear flaps near the launcher the day MH17 was shot down; their outfits were different to the Russian-backed rebels'.

Berger has asked the court for a second interrogation of witness X48.

"The Public Prosecution Service still sees reason for further questions, at least about the four soldiers with the same, different uniforms and tank caps," he said.

"The (witness) statement does not indicate whether the witness saw these four soldiers in or near the Buk-TELAR."

The court has previously heard that Russian military and intelligence agents were seen at the launch site.

Investigators have also identified the missile launcher in question as number 3X2 from the 53rd Russian Anti-Aircraft Brigade.

The JIT could find no evidence of the weapon in Russia between June and July 2014.

In fact, Berger says, all available photos, videos and satellite pictures place it in eastern Ukraine but Russia has refused or ignored repeated requests to account for the weapon over that period.

"We have reminded Russian authorities several times about our outstanding questions about TELAR 3X2," Berger said.

"The governments of the JIT countries have also called for an answer at diplomatic level without result."

Investigators have also unsuccessfully pressed Russia to reveal the identities of the missile launcher's crew during that period, but are hopeful X48 may provide answers.

After six long years, the dragnet appears to be closing on the individuals who fired the missile that shot down MH17.

"We believe that this investigation has been nearly completed," Berger said in court last week.

If the culprits are found to be Russian soldiers it would explain the Kremlin's campaign of obstruction and deception.

Like the four men already on trial in absentia, the culprits may never face court.

But for the families of those who were on board MH17, identifying those who shot down the plane will provide further answers, and some solace.

The JIT is determined not to leave them wondering.

Australian Associated Press