An oil rig worker who claimed to have spotted a burning plane, in which he believed to be the missing Malaysia Airlines (MAS) flight MH370 off the coast of Vietnam, has been sacked by his employer.

New Zealander Mike McKay was working on the Songa Mercur oil rig off the Vietnamese coast on March 8, the same time when the Boeing 777 aircraft carrying 239 passengers and crew members went missing.

He first sent an email to his employers regarding the incident, urging them to forward the information to the authorities. When he didn't get any response, he forwarded the same email to the Vietnamese authorities and the New Zealand Embassy a few days later, relating what he had seen that day.

"Gentlemen. I believe I saw the Malaysia Airlines flight come down. The timing is right," he wrote in his email.

"I tried to contact Malaysian and Vietnamese officials days ago. But I do not know if the message has been received.

"I am on the oil rig Songa-Mercur off the coast of Vung Tau. The surface location of the observation is Lat 08 22’ 30.20” N Lat 108 42.22.26” E.

"I observed (the plane?) burning at high altitude at a compass bearing of 265* to 275*"

The Songa Mercur oil rig off Vung Tau, on the south east coast of Vietnam is located in the same general area where a Chinese satellite spotted a suspected crash site.

McKay says he spotted the missing flight MH370 on fire in the sky from his rig early on March 8.

Following the publication of his email, which was subsequently leaked to the media, the rig operator, Idemitsu and McKay’s contractor and rig owner, Songa Offshore, were inundated with inquiries that blocked their communications, McKay told New Zealand’s Sunday Star Times.

“This became intolerable for them and I was removed from the rig and not invited back,” he said.

Vietnamese officials interviewed McKay in Vung Tau and were going to act on his sighting but the search moved to the Andaman Sea two days after the interview, McKay said.

Vietnamese naval officer Le Minh Thanh told America's ABC News that Vietnamese officials sent a plane to the area to investigate McKay's claims, but the search was fruitless.

On March 8, Acting Transport Minister Datuk Seri Hishammuddin Hussein had dismissed the information as untrue after obtaining confirmation from the Department of Civil Aviation (DCA) and the Foreign Minister.

He said there was no information yet on the Boeing 777-200 aircraft or any wreckage found at sea.

Last week, a woman who had been sailing between India and Thailand during the time flight MH370 disappeared from radar, said she too may have seen the airliner on fire, but in a different location.

Katherine Tee, 41, was standing on the deck of her yacht in early March when she claimed to have seen a plane surrounded by bright orange light with a tail of black smoke.

She said she only recently reported her sighting to the Joint Agency Coordination Centre (JACC) in Australia because she didn’t think anyone would believe her at the time.

Flight MH370 went missing shortly after departing the Kuala Lumpur International Airport and remains missing despite an international search involving over two dozen countries, mainly in the Indian Ocean.