Mystery has surrounded MH370 since it’s disappearance. Here’s a look at the theories suggested over the years.

EXCLUSIVE

Authorities are actively investigating a possible link between the discovery of two suspected MH370 fragments that washed up on Madagascar and the assassination of a Malaysian diplomat, it can be revealed.

Honorary Consul of Malaysia Zahid Raza was gunned down in the centre of the island nation’s capital Antananarivo on August 24, 2017 — eight days after American plane hunter Blaine Gibson handed over the “promising” pieces of debris to local police via an associate.

Mr Raza had been tasked with the job of escorting the wreckage to Kuala Lumpur for analysis but was murdered before he could do so.

In an exclusive interview with news.com.au, Mr Gibson has revealed those two fragments never made it to Malaysia.

Instead — more than 18 months on — they are gathering dust in an undisclosed location in Madagascar while the probe into Mr Raza’s murder continues.

Mr Gibson said MH370 investigation team chief Kok Soo Chun told him Malaysia had requested delivery of the fragments but had yet to receive a response.

“The diplomat was murdered eight days after I handed those pieces in,” Mr Gibson told news.com.au.

“I don’t know if they are related, but the timing is highly suspicious.”

The refusal of Madagascar police to surrender the parts suggests they are not ready to rule out a possible link between the diplomat’s murder and MH370.

That’s despite speculation Mr Raza was killed as payback for his alleged involvement in the 2009 abduction of several residents of Indo-Pakistani descent known collectively as Karens.

“Zahid Raza was the manager of an office supply business, Z & Z Center, in the Malagasy capital. He lived a few years in La Reunion before returning to Madagascar about three years ago to take up the post of consul in Antananarivo,” French-language news website ZINFOS 974 said in an article published a day after the slaying.

“In Madagascar, his name is associated with the kidnapping of members of the Karen community in Fianarantsoa in 2009. Suspected of having participated, he is imprisoned in Tsiafahy and then in Antanimora prison. He was able to return to his country freely in December 2010, provoking indignation within the Karen community.”

‘HE WILL NOT LEAVE MADAGASCAR ALIVE’

Mr Gibson has been credited with finding more than half of 32 pieces of suspected MH370 wreckage that have washed up on the Indian Ocean islands of La Reunion, Rodrigues, Madagascar and Mauritius and the coastlines of South Africa and Mozambique.

While only three parts have been declared “100 per cent” because they feature serial numbers that could be matched to the missing Boeing 777, several others are categorised as “highly likely” to have come from MH370.

Mr Gibson, an American lawyer and explorer who has travelled to all but 10 of the world’s 195 countries and speaks six languages, began an independent, self-funded investigation into MH370 in 2015.

At first his mission took him to Cambodia and Myanmar to explore the possibility the plane had flown north. He then travelled to the Maldives to investigate (now discredited) sightings by fishermen of a plane on the morning MH370 vanished.

He also travelled to Australia to explore coastlines on Western Australia and South Australia before the discovery of the first confirmed piece of MH370 — a wing part known as a flaperon — washed up on La Reunion and narrowed down his search.

In February 2016, Mr Gibson and a local man found a large triangular chunk of metal washed up on a sandbank in Mozambique that became known as the “No Step” piece.

“I went out and searched along the shorelines, and I started to find pieces of the plane,” Mr Gibson said.

“Many other people were also finding pieces of the plane, debris that was naturally washing ashore, and they would bring them to me. I told the local people what to look for and offered small rewards.

“People started questioning how it could be that I was finding all these plane parts — which in fact were found by many different individuals, not just me — and it became another conspiracy.

“But I was only doing as a private citizen what the authorities should have been doing themselves — which was searching the coastlines where debris started turning up.”

Inevitably, people started gossiping about Mr Gibson’s intentions, spreading false rumours about the debris having been planted and even suggesting his ability to speak six languages was proof he was a spy.

The hostility intensified when he took his search to Madagascar, and he started receiving death threats.

“The death threats began in December 2016,” Mr Gibson told news.com.au. “(On one occasion) Someone called a friend of mine and warned them that I would not leave Madagascar alive. A few months later, the diplomat was murdered.”

HORROR NEW CONSPIRACY THEORY

This week Mr Gibson has found himself the target of a particularly vicious — albeit far fetched — smear campaign.

A pair of MH370 obsessives, Andre Milne and Daniel Boyer, have accused Mr Gibson of “pillaging” the debris field of MH17 and passing off the fragments as MH370 wreckage.

“We have identified evidence that said suspect Blaine Gibson has personally tampered with and or planted aerospace debris wreckage in the matter of MH370,” Mr Milne wrote in an email to news.com.au.

“As such, should evidence be discovered that verifies the crash site of MH17 was pillaged, any and or all parties directly and or indirectly associated with said pillaging ‘may’ be subject to prosecution for participating in a war crime.”

Mr Boyer aired his allegations in a UK tabloid, telling the Express he found it “suspicious” Mr Gibson had found so much wreckage.

“It’s hurtful and defamatory and scary, and I’m trying to figure out why they are doing it,” Mr Gibson told news.com.au.

“The death threats, the stalking, the intimidation has been going on for more than two years. I’ve stopped posting my location (on social media). I do find myself looking over my shoulder in a state of fear wondering if somebody is going to in fact kill me.

“I don’t know if it’s lone individuals protecting their pet (MH370) theories or if it’s part of a campaign of disinformation or something more sinister.”

Malaysian Airlines flight 370 vanished on March 8, 2014, 40 minutes into a flight from Kuala Lumpur to Beijing, with 239 people on board.

Satellite data indicates it travelled south for several hours before crashing into the remote southern Indian Ocean off Western Australia.

However, a three-year search by the Australian Transport Safety Bureau (ATSB) failed to find any trace of the plane.

A second mission by underwater exploration company Ocean Infinity last year also failed to locate the wreckage.