Russians Igor Girkin, Sergey Dubinsky and Ukrainian Leonid Kharchenko aren't taking part in proceedings in the District Court of the Hague over the downing of MH17 on July 14, 2017, in eastern Ukraine.

All 298 aboard the passenger plane died, including 38 who called Australia home, when it was shot down by a Buk missile.

Fourth defendant Oleg Pulatov is yet to take a position and his lawyers have made scores of requests for fresh investigations.

Prosecutor Ward Ferdinandusse says the trial of his co-accused shouldn't be delayed.

"The rights and interests of the other three suspects, the next of kin and society in a broader sense, demand that the three default cases be completed expeditiously and not be kept on hold pending the moment that Pulatov wishes to state his trial position," he told the court.

District Judge Hendrik Steenhuis is due to rule on Pulatov's requests on July 3.

Ferdinandusse said the Russian seemed to be on a "fishing expedition" for a defence by requesting investigations of multiple crash scenarios.

"Pulatov lurks in the early-morning fog of a defence to be drafted later," he said.

"As he says himself, the result of these investigations could be the MH17 cannot have been hit by a Buk missile."

Prosecutor Thijs Berger says Pulatov can make specific investigation requests to use for his defence, but he doesn't have the right to request a general check of the investigation.

"No country in the world that raises a murder suspect to the position of being an official investigator, it is simply not his role," he said.

Berger also cheekily suggested that Pulatov could claim combatant immunity if he admitted he was fighting for Russia when MH17 was brought down.

"We would be delighted to hear his side of the story," he said.

Defence lawyer Boudewijn van Eijck said his client had a right to make the requests.

But he said the defence was in a "David and Goliath situation" in relation to evidence that has characterised many recent Dutch legal cases.

"This case can be a moment in which the defence can be given more possibilities in relation to others," van Eijck said.

Meanwhile, Berger expanded on the Australian Federal Police role in indentifying part of Buk missile found in the MH17 wreckage.

Berger says the AFP analysed more than 120 photographs to prove that a lump of metal found lodged deep in the plane's window frame was a base plate from either a 9M38 or 9M381 Buk missile.

"This is a connecting piece joining the rocket to the Telar and it's there before the missile is launched. This covers that connection point," he told the court.

"The meticulous manner in which this investigation took place is described in the AFP report."

Australian Associated Press