The Australian Maritime Safety Authority (AMSA) says it has received an expert assessment of commercial satellite imagery of objects it suspects may be debris from the flight.

AMSA spokesman John Young says the images indicate that one of the objects measures around 24 metres in length.

Mr Young has emphasised the objects may be difficult to locate and they may not be related to the search.

"The objects are relatively indistinct on the imagery. I don't profess to be an expert in assessing the imagery, but those who are expert indicate they are credible sightings," he said.

AMSA says it is "doing its level best" to find any possible survivors.