Australian researchers today said they have detect a low-frequency underwater noise off India's southern tip at about the time MH370 mysteriously disappeared, as a British woman sailing from Kochi to Phuket in March claimed that she may have seen the plane on fire. (Read: Australia Probes Possible MH370 Witness Account)

The researchers detected the mysterious noise, possibly that of an ocean impact, recorded by two undersea receivers in the Indian Ocean about the time the Malaysia Airlines plane ceased satellite transmissions and vanished on March 8 with 239 people on board. (Read: Underwater Sound Examined for Links to Missing Jet)

The researchers released an audio recording today of the underwater sound that they say could possibly be related to the final moments of the missing Boeing 777. (Read: Recorded Noise Might Offer Clues to Missing Plane)

"It's not even really a thump sort of a sound ? it's more of a dull oomph," Alec Duncan, a senior marine science research fellow at Curtin University near Perth, who has led the research, told The New York Times.

The general vicinity from which the noise come is a large area of the central Indian Ocean off the southern tip of India and about 3,000 miles northwest of Australia.

But that is not reliable with calculations of an arc of possible locations in the southeastern Indian Ocean where the plane might have run out of fuel.

Those calculations were from Inmarsat, the global satellite communications company. Scientists have struggled to figure out the origin of the noise. (Read: Maths Formulas Could Find Missing MH370: Report)

"If you ask me what's the probability this is related to the flight, without the satellite data it's 25 or 30 per cent, but that's certainly worth taking a very close look at," Duncan said.

Adding to the uncertainty surrounding the plane's possible final location, a British woman sailing with her husband across the Indian Ocean from Kerala's port city of Kochi to Phuket in Thailand has claimed she may have seen the plane on fire.

Katherine Tee, 41, reported on Sunday to the Joint Agency Coordination Centre (JACC) that is leading the MH370 search that she was on night-watch on the couple's 40-feet boat when flight MH370 vanished.

The couple have since re-checked their sailing logs and believe they were near one of the projected flight paths for the aircraft, now missing for nearly three months.

Tee, who was at sea for 13 months, said she did not report the sighting at the time because of marital issues and because she feared being mistaken.

"I saw something that looked like a plane on fire. Then I thought I must be mad. It caught my attention because I had never seen a plane with orange lights before so I wondered what they were...," she told the Phuket Gazette.

Media reports said Australian authorities were looking at Tee's claim.

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