The Hunt for MH370 author Ean Higgins finds most likely scenario for loss of Boeing 777

Author Ean Higgins is confident MH370 will eventually be found in the Indian Ocean. Photo / Supplied

Author Ean Higgins has zeroed in on what most likely happened on board MH370 during its final flight - a meticulously planned and coldly executed mass murder-suicide.

Five years after the Malaysian Airlines aircraft disappeared, his new book outlines a series of scenarios that could have led to its disappearance with 239 people on board.

In The Hunt for MH370 he draws on years of interviews with aviation experts, victims' families, air crash investigators, professional hunters and the one the veteran journalist favours is the "rogue pilot to the end".

Troubled captain Zaharie Ahmad Shah effectively high jacked his own plane by locking his co-pilot out of the cockpit early in the flight from Kuala Lumpur to Beijing.

He then turned off tracking gear, depressurised the plane - soon killing the others on board - did a U-turn while he put on his pilot's oxygen mask with hours of supply, and set a course for the southern Indian Ocean.

There he ditched the plane causing minimum damage so not to create a debris field for searchers to easily find. He wanted to commit the perfect crime.

''In an act of mass murder-suicide he made a jetliner, himself and the 238 innocent souls on board vanish without a trace in one of the world's deepest, wildest and most remote stretches of sea,'' he writes.

Why?

''That I just don't know. It is still baffling, there was alot going on his life - there were women, there was politics but sometimes you just don't know,'' he told the Weekend Herald.

And he concedes, after trawling all the evidence, there's no certainty over what happened to the Boeing 777.

''Until we find the aircraft and recover the black box we won't know for sure what happened to MH370.''

He's troubled by the wild theories that get recycled in the news, causing more pain for relatives, some of whom he interviewed.

There's the one about the plane down in the Cambodian jungle and the one about passengers still alive and being held hostage.

''We've found parts of the aircraft washed up on the other side of the Indian Ocean, some things we do know. We have a pretty good idea of the rough track it flew at the end from the satellite data,'' Higgins said.

''What is really tragic is that some of the Chinese families in particular still have some thought that it flew the other way and maybe their relatives are hostages in a Taliban camp.''

He's been on the big Australian papers for four decades, and knows what grabs a headline but these stories go too far.

''While I'm loathe to criticise other people in my profession some of these things are just absurd.''

Higgins has spent time in New Zealand reporting, and in 2010 was at the centre of an uproar over his questions at press conferences following the Pike River disaster.

When he asked why a ''country cop'' was leading the response instead of mining experts the backlash was swift and harsh. He was described by Kiwi politicians as "disgraceful,", "boorish" and an "utter toss pot".

He said he's been to war zones and done some tough stories but a retreat back home to Australia for the weekend couldn't come soon enough for him back then.

''It became an international incident. Everyone loved bashing the Australian bastards, the rude Australians.''

There is a big parallel between the Pike River explosions, which killed 29 men, and the loss of MH370.

Relatives in both tragedies wanted justice done and to recover their loved ones.

''It's an inherent human thing to want to retrieve your dead.''

Higgins believes the plane is somewhere in the '' Seventh Arc'' satellite zone in the Indian Ocean, not so far away from two massive searches have already been done.

''They may have to look further afield from that area they've already searched or it may have been just 100m away.''

It may take many more years to find the plane. Technological advances will help, but it will need a big conglomerate to do the job.

He said China could win friends by funding it and he urges Boeing to follow the lead of
Airbus which partially paid for and provided logistical support for a two-year search for a plane off the coast of Brazil.

He believes the chances are ''very good'' of finding the MH370 which is essential for finding out what happen end and to help relatives.

''Someone eventually finds these things - you may have gaps. No big passenger aircraft that has gone down in the sea has been left un found.''

New Zealander Danica Weeks husband, Paul was on board, and she was interviewed in depth for the book.

''It still tortures her every day and she won't be released until she finds him. And that's true of the others.''