Insight - All at sea: Australia's search for MH370 under scrutiny

The Royal Australian Navy ship HMAS Perth is guided into position by a Royal New Zealand Airforce (RNZAF) P-3K2 Orion aircraft to recover an object in the southern Indian Ocean, as the search continues for missing Malaysia Airlines flight MH370 April 13, 2014. REUTERS/Greg Wood/Pool

SYDNEY (Reuters) - Nearly a year after embarking on a multi-million dollar quest to solve one of aviation's greatest unsolved mysteries, authorities and search teams are being criticised over their approach to finding Flight MH370 in the remote southern Indian Ocean.

The Australian-led search, already the most expensive in aviation history, has found no trace of the Malaysia Airlines jet or its 239 passengers and crew, prompting calls for a rethink into the way the mission is conducted.