Australian Prime Minister Tony Abbott warned on Tuesday of a potential cover-up in the investigation of the downed Malaysian Airlines MH17, lashing the " evidence tampering on an industrial scale."

The prime minister said Air Chief Marshall Angus Houston, who has been responsible for the MH370 investigation, is leading the work on Operation Bring Them Home, coordinating consular officials in Ukraine and the Netherlands, federal police, disaster victim identification and forensic experts.

"This is necessarily a painstaking and methodical process that will take some weeks," Abbott said. "As frustrating as this is, we do have to get it right. It would be terrible to compound families ' grief by risking the misidentification of their loved ones."

Abbott confirmed that DNA samples were being taken from families of the victims to help identify remains.

He said that anyone who had seen television footage of the crash site would understand there was "a long, long way to go" for a full investigation of the tragedy.

"After the crime, comes the cover-up. What we have seen is evidence tampering on an industrial scale and obviously that has to stop," he said.

Abbott said the crash site had been trampled from the beginning of the tragedy and "we haven't just seen all sorts of random individuals roaming around the site picking over remains, picking over wreckage, we've seen heavy equipment coming onto the site."

"It looked more like a garden clean-up than a forensic investigation, the more recent footage suggests that it's more like a building demolition than a forensic investigation," he added.