LONDON- "What exactly are they trying to hide?" President Barack Obama asked Monday as he demanded that Ukrainian rebels give investigators access to the wreckage of the downed jetliner.
The answer is: potentially a lot.
Aviation and defense experts say the victims' bodies could contain missile shrapnel. Chemical residue on the plane could confirm the type of weapon that brought down Malaysia Airlines Flight 17. And the location of the wreckage could yield information on how the attack unfolded.
AP Photo/In this Sunday photo, a satellite image shows the primary crash site, at left, of Malaysia Airlines Flight 17 located near Hrabove, eastern Ukraine.
The black boxes could offer vital clues as well. The cockpit voice recorder would record the bang of a missile. The data recorders, which register altitude and position, would be able to tie that information to the timing of a known missile launch in the area.
"You can effectively backtrack and give a relatively high degree of confidence in the location where that missile took off from," said a Manchester, England-based aviation industry consultant, Chris Yates. "If that location happens to be in rebel-held territory, which we all suspect it is, that would be the first point where you could point the finger of blame."
But while anguished families waited to take possession of their loved ones' remains, and investigators waited for the rebels to hand over the black boxes, independent observers warned that the pro-Moscow separatists had tampered with the debris and failed to secure the crash site. And the U.S. and its allies fumed that the rebels are trying to cover up evidence they shot down the plane.
Yates warned that the rebels may have already compromised the probe.
"What is gained, of course, is the possibility that whatever evidence remains of a missile strike can be obliterated," he said. "That's the bottom line, I suppose."
In this still mysterious tragedy, for example, the bodies themselves could offer precious clues. A missile from a Russian-made SA-11 mobile launcher, also known as a Buk, would explode outside the target aircraft, hurling shrapnel into the plane. Some bodies might bear the telltale wounds.
"While the stated reasons for removing some of the bodies to a refrigerated train - to protect them from wild animals and slow their decomposition - may be genuine, the bodies, too, are evidence," said Keir Giles, an expert on security at the Chatham House think tank.
Lyubov Kudryavets, a worker at the Torez morgue, told The Associated Press that last Thursday, after the plane went down over eastern Ukraine, a resident brought in the bloody body of a child, about 7 or 8 years old. On Saturday, she said, pro-Russian militiamen came to claim it.
"They began to question me: 'Where are the fragments of rocket? Where are the fragments from the plane?'" Kudryavets said. "But I didn't have any wreckage. ... I swear."
Rebel leader Alexander Borodai has denied he and his comrades-in-arms were trying to tamper with evidence, saying the bodies would be turned over to Malaysian experts.
As of Monday, the remains of 282 people had been reported recovered.
A total of 298 people were killed in the downing of the Boeing wide-body jet; some bodies may have been all but obliterated.