Malaysia’s prime minister says his nation remains committed to the so-far fruitless hunt for flight MH370 exactly one year after it went missing.

Najib Razak’s comments came as Australian Prime Minister Tony Abbott said the search in the southern Indian Ocean, could be widened if the current probe is unsuccessful.

“Together with our international partners, we have followed the little evidence that exists. Malaysia remains committed to the search, and hopeful that MH370 will be found,” Najib Razak said in a statement on Sunday to mark the anniversary of the plane’s disappearance.

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The year-long hunt in the deep ocean at least 1,600km off the coast of Western Australia, where the Malaysia Airlines Boeing 777 is believed to have crashed, has so far yielded no sign of the plane.

An independent team of investigators tasked with probing the mystery was to release an interim report on its findings on Sunday at 6pm (AEDT) in Kuala Lumpur.

It remains unclear whether it will contain any new information on what might have caused the aircraft to disappear after veering from its Kuala Lumpur-Beijing route on March 8 , 2014, with 239 passengers and crew aboard.

“No words can describe the pain the families of those on board are going through,” Mr Najib said, calling the plane’s disappearance “without precedent”.

“The lack of answers and definitive proof – such as aircraft wreckage – has made this more difficult to bear.”

Malaysia Airlines chief executive Ahmad Jauhari Yahya told relatives of the crew on the flight the carrier’s management shares their ongoing grief.

“We remain hopeful that the search will help us find the answers that we all seek,” Ahmad Jauhari told staff at a remembrance ceremony in Kuala Lumpur.

“Until then, as a family, we will continue to support to each other.”

Investigators still lack any trace of the jet, including the “black box” data recorders considered most likely to yield clues.

More than 40 per cent of a designated 60,000-square-kilometre zone believed to be the most likely location of the crash site has been scanned for wreckage using sophisticated sonar, but nothing related to MH370 has been found.

The priority search is due to conclude in May.