Analysis: Promising lead on missing Malaysian plane

In an interview with Al Jazeera, Tom Ballantyne, an aviation expert, said Abbott's announcement could be "the most promising" development since the plane disappeared.

"Although the word caution, I think, is the most important one here," he said from Sydney. "We've had so many false leads in this story, and we probably have to wait for several hours, before we get a real defining detail of what these objects are in the water."