Flight officer Rayan Gharazeddine looks out of a Royal Australian Air Force (RAAF) AP-3C Orion as it flies over the southern Indian Ocean during the search for missing Malaysian Airlines flight MH370 March 22, 2014. [Photo/Agencies]

SYDNEY - The search for the missing Malaysian Airlines flight MH370 has been called off, in a joint statement made by Australian, Malaysian and Chinese governments on Tuesday.

For the past two years, authorities have combed a 120,000 square km patch of the Indian Ocean to no avail, with no sign of the plane yet to be found.

"Despite every effort using the best science available, cutting-edge technology, as well as modeling and advice from highly skilled professionals who are the best in their field, unfortunately, the search has not been able to locate the aircraft," the statement said.

"The decision to suspend the underwater search has not been taken lightly nor without sadness."

The Malaysian Airlines flight went off the grid in March 2014, with 239 passengers on board heading for Beijing from Kuala Lumpur.

The governments did not make the decision lightly, but were unable to find any credible evidence that a continued search would generate a successful outcome.

"Whilst combined scientific studies have continued to refine areas of probability, to date no new information has been discovered to determine the specific location of the aircraft," the statement said.

"We remain hopeful that new information will come to light and that at some point in the future the aircraft will be located," it said.

The end of the hunt raises the prospect that the world's greatest aviation mystery may never be solved.