Australia had always been transparent that the search for the missing MH370 was challenging.

Prime Minister Tony Abbott told Radio 6iX that the incident surrounding the missing Malaysian airlines is "one of the great mysteries of our time."

Unfavourable weather conditions had also hampered search efforts on top of baffling information about the flight's telemetry.

In an Interview with ABC Australian Air Chief Marshal Angus Houston said that MH370 was the most complex search he handled.

"In other words, we don't have a precise aircraft location for six hours before the aircraft went into the water somewhere. The reality is it's the most complex and challenging search and rescue operation, or search and recovery operation now that I've ever seen."

However, Mr Houston assured Malaysia that "Australia is doing everything it can" and Australia has all the grieving families in mind as it conducts its search.

"It is a truly international effort and powerful example of international cooperation at its very best. I'd like to personally extend my personal condolences to the people of Malaysia," he said.

On Wednesday, Australia's Joint Agency Coordination Centre faced the difficulty of their task as isolated thunderstorms and sea fog blocked visibility.

Desperation looms as the search efforts was now focused to unmapped territory of the southern Indian Ocean, 1,500 km west of Perth.

So far, all international efforts were rendered futile as the mystery remained unsolved.

In Malaysia, police investigators were even scrutinizing cargo of mangosteens and off served onboard.

"For example, when we knew there was a load of mangosteens onboard, we had to find out where the mangosteens came from. We tracked down who plucked the fruits, who packed them and shipped them out, and who put them on the plane. Then we had to determine who would have received them in China and who paid for it, and for how much. Imagine how many people we must interview to rule out sabotage and that is just the mangosteens," Inspector-General of Police Tan Sri Khalid Abu Bakar said.

Mr Khalid explained that all aspects should be explored to rule out the angle of sabotage.