"That's entirely consistent with the lack of debris coming onshore."

The abundance of junk in the ocean has also meant that even if MH370 items washed ashore, in would be difficult to confidently link them to the missing airliner.

The task of tracking MH370 debris movements was made even more difficult because search teams didn't know precisely where the plane plunged into the ocean, Mr Griffin said.

"The big unknown is the splash point," he said. "That's never been known."

MH370 disappeared on March 8, 2014, with 239 people on board. Satellite systems have been used to place the presumed wreckage deep in the Indian Ocean.

Authorities involved in the search believe the plane spiralled into the ocean after running out of fuel – as opposed to a "controlled" ocean landing – which should have created a lot of debris.

Initial drift models suggested debris could come ashore on Indonesia's West Sumatra about four months after the suspected crash.

While oceanographers could have used any early debris sightings to possibly find the crash site, the long time that has elapsed since means the task of "back tracking" is almost redundant now.


A spokesman for the Australian Transport Safety Bureau, which is responsible for the underwater search, said the main value of finding debris would be in providing some level of answer to families of those on MH370.

"There is, of course, no guarantee that there was any floating debris or that, if there were, it would have been recognisable as coming from MH370," the spokesman said.

"While we are looking forward to the results, we are not relying on the prospect of floating debris being found in order to find MH370."

There is no agreed theory as to why MH370 left Kuala Lumpur en route to Beijing, only to cross back over the Malaysian peninsula with its communications systems switched off.

The underwater search of the 60,000-square-kilometre priority zone is scheduled to finish in late May. If the debris field has not been located by then, authorities would need to commit further funding to search lower-priority areas or call off the search.