Image copyright Reuters Image caption Almost three years of searches haven't solved the mystery of what happened to the plane (File photo)

The deep-water search for Malaysia Airlines flight MH370 has been called off, without the plane being found.

There is an even greater chance now that we will never know what happened to those 239 people who boarded a flight to Beijing from Kuala Lumpur on 8 March 2014 and then vanished.

The decision to call off the search - which has scoured 120,000sq km (46,332 sq miles) of sea floor in the southern Indian Ocean - was not entirely unexpected. The three countries involved - Australia, Malaysia and China - had agreed last year that unless they found major new evidence, they would suspend operations.

But informed experts and relatives of the passengers are dismayed, saying that this major new evidence does exist, and if they keep looking, they will find it.

"Commercial planes cannot just be allowed to disappear without a trace," said Voice370, a group supporting relatives.

"Stopping at this stage is nothing short of irresponsible, and betrays a shocking lack of faith in the data, tools and recommendations of an array of official experts assembled by the authorities themselves."

The 120,000sq km area of Indian Ocean off southern Australia was chosen based on satellite data as the most likely place the Boeing 777 could have come down along what is presumed to have been its flight path.

"They picked the area based on the best information that was available at the time," says Don Thompson, a British engineer who is part of the Independent Group, a handful of informed experts around the world who have been investigating MH370 themselves.

"But everything seems to point a little further north-east, which is where the ATSB's most recent review is pointing."

That's the Australian Transport Safety Board, which has been co-ordinating the underwater search. It said in December that there was "a high degree of confidence" the plane was not in the specified search zone.

That was starting to look fairly obvious, as there was only a fraction of the defined area left to search.

But the report also recommended searching a 25,000sq km area to the north of the presumed flight path.

Image copyright Atsb Image caption Relatives of passengers oppose the end of deep-water searches (File photo)

It drew on new information by the Commonwealth Scientific and Industrial Research Organisation (CSIRO), which analysed where confirmed debris from the plane washed up and used that to narrow down where it must have come down.

The report concluded that "if this area were to be searched, prospective areas for locating the aircraft wreckage, based on all the analysis to date, would be exhausted".

'Evidence has been ignored'

"When CSIRO came out with that drift analysis I was really excited," says Blaine Gibson.

He has become something of a legend in MH370 circles for his self-funded trips to Malaysia, Mauritius and the Maldives looking for answers. He has found several pieces of debris which contributed to the new theory.

Image caption Some items of luggage found by Blaine Gibson on a beach in Madagascar last year

"I really thought they would extend the search," Mr Gibson said. "The debris that I and other people have found resulted in very strong scientific evidence and it's been ignored."

Blaine Gibson believes other evidence has been ignored, including reports from people in the Maldives who say they saw something fall from the sky the day the plane vanished. He blames an "overreliance" on the early satellite data, which put false hope in 120,000 sq km.

"It's like saying we're not going to look for it until we find it."

The relatives' group, Voice370, says searching the newly defined area is "an inescapable duty owed to the flying public in the interest of aviation safety".

Image copyright EPA Image caption Relatives say finding out the cause of the crash is important to improve air travel security

So will it happen? At the moment there is no indication it will.

The search has already cost $145m (£118m) and it's not clear who would be prepared to pick up such a tab again.

Don Thompson says China, which has provided one of the specialist search ships, has acquired further equipment in recent months and could perhaps step in. Most of the passengers were after all Chinese. But there's no indication of that as yet.

"It needs a bit of political will to get it going, some sort of organisation so it can lobby the right entities," he says.

Media playback is unsupported on your device Media caption Grace Subathirai Nathan, daughter of an MH370 victim, says it is premature to call off deep-water searches

Geoffrey Thomas, aviation expert and editor of the Airline Ratings website, believes the plane will be found, and that it might be a private consortium that does it, including Boeing - who made the missing plane - and its engine-maker, Rolls Royce.

"It's important from an industry perspective to find this plane because the 777 is the backbone of the world's international long haul fleet," he said.

"We need to know that plane is safe. It's possible that it could have been a series of failures that sparked this disaster but we just don't know."

Experts agree that if the search is to continue, it has to happen immediately or never will.

"Dismantling all the infrastructure that's been built up is a tragedy because it will cost millions to re-establish it," said Mr Thomas.

Will we ever know what happened?

There are still huge gaps in our information about flight MH370. We don't know why the plane made a mysterious turn to the west about an hour after taking off from Kuala Lumpur, and why its tracking was turned off.

Mr Thompson points out that the plane would also have crossed five different military radar stations - two in Indonesia, one Thai and two on India's Andaman Islands - but they "apparently they saw nothing".

Media playback is unsupported on your device Media caption Flight MH370: Audio recording reveals final cockpit communications

Many have speculated about a pilot murder/suicide, but this has been ruled out by most informed observers. There's no evidence pointing to such intentions, and we know from the fact the plane broke up on impact that it was not being controlled at the time.

Blaine Gibson says that until the black box or a debris field are found which prove beyond doubt it was an accident, "we have to be open to the hijacking possibility and the accident possibility".

Perhaps there's even been a cover-up, he says. But he believes that if that's the case, eventually "someone's going to talk".

"I think we're going to get answers in my lifetime," he says, "perhaps when we least expect it".

"I have to put my faith and hope in science, in perseverance and in justice to say that we're going to know."