Defence lawyers have denied believing "conspiracy theories" about the downing of Malaysia Airlines Flight 17 after requesting that every possible scenario be investigated again in a Dutch court.
Lawyer Sabine ten Doesschate is representing Russian Oleg Pulatov, who's accused along with three other men of coordinating the missile launcher used to shoot down the plane in Ukraine, killing all 298 people aboard, including 38 Australian citizens and residents, on July 17, 2014.
Prosecutors have told the District Court of the Hague that a Buk-TELAR launcher fired a missile at MH17 from an area held by Russian-backed separatists.
But Ms ten Doesschate and associate Boudewijn van Eijck have applied for every possible crash scenario to be probed again.
The defence are focused on three alternate theories: that MH17 was either shot down by a Ukrainian fighter jet; a Ukrainian surface-to-air missile; or rebels by accident because Ukraine's airforce was using passenger planes as "human shields".
The international Joint Investigation Team, which includes Australia, has already investigated the crash for six years and if granted, the defence applications could drag out criminal proceedings indefinitely.
"I've seen ideas put forward like these are just strategies, they're just trying to put a spanner in the works, they want to confuse things, they want to cause delays," ten Doesschate told the court on Tuesday.
"I've seen direct messages from people who are asking why are we taking (on) something which people call conspiracy theories, why are we believing these."
"It's not that we believe; the defence has to look at alternative scenarios.
"These are not strategies, it's the actual task of the defence to look critically at what has said to be established in the case file, and to obtain information the basis of which we can check the correctness and reliability of various facts."
She also took a swipe at the JIT and the prosecution saying their conclusions were "oversimplified" and based on assumptions that are not supported sufficiently by evidence.
Ten Doesschate said that was despite the JIT having numerous investigators working on the case over six years and an annual budget of at least 9 million euros ($A15 million).
"Such an investment of time and money should have meant that no arguments would be left about the facts," she said.
Dutch prosecutors said they would try to respond to the defence requests when the pre-trial resumes on Friday.
District Judge Hendrik Steenhuis said the court would endeavour to rule on the defence and prosecution investigation requests by June 3.