Malaysia has formally declared missing flight MH370 an “accident” and its passengers and crew presumed dead, a step that opens the door for compensation payments but which was met with scepticism by distraught relatives.

“It is therefore, with the heaviest heart and deepest sorrow that, on behalf of the government of Malaysia, we officially declare Malaysia Airlines flight MH370 an accident,” civil aviation chief Azharuddin Abdul Rahman said in a televised announcement on Thursday.

“All 239 of the passengers and crew on board MH370 are presumed to have lost their lives,” he added.

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Azharuddin said the official decision that the plane’s disappearance on March 8 was an accident would allow families to move on and receive payments from the airlines.

“It is hoped that this declaration will enable families to obtain the assistance they need, in particular through the compensations process,” he said.

But Sarah Bajc, whose partner Philip Wood was on board the plane, poured scorn on the announcement.

“I think they are lying,” she said.

“It could very well be that the plane crashed. But there is no evidence, and until there is evidence we just can’t believe them,” she said, referring to the Malaysian government and airline.

“It is impossible to bring any closure until we have proof.”

Some relatives accuse the Malaysian government and its flag carrier of a chaotic and bungled response to the plane’s initial diversion, which allowed the jet to disappear, and a subsequent cover-up.

Kuala Lumpur and Malaysia Airlines strenuously deny these charges.

MH370 vanished en route from Kuala Lumpur to Beijing in what remains one of history’s great aviation mysteries.

Malaysian authorities say satellite data indicates the plane inexplicably detoured to the remote southern Indian Ocean, which they suspect was due to “deliberate” action on-board.

But no firm evidence has turned up yet, despite an ongoing Australian-led search of the supposed crash region – the most expensive search and rescue operation in history.