MH370 search vessel sinks after crashing into volcano

The vessel collided with a 2,200-metre underwater mud volcano

There were no injuries to the crew of the Fugro Discovery (ATSB)

A deep-sea sonar vehicle searching for Malaysia Airlines flight MH370 has sunk to the ocean floor after colliding with an underwater mud volcano.

The collision with the 2,200-metre mud volcano on Sunday broke the cable between the sonar vehicle, known as a towfish, and the Fugro Discovery search vessel.

The towfish and 4,500 metres of cable are now resting on the floor of the Indian Ocean, the Joint Agency Coordination Centre (JACC) said in a statement.

The towfish maps the seafloor using sonar (ATSB)

There were no injuries to the crew of the Fugro Discovery, and it is believed the towfish can be recovered later.

MH370, which was carrying 12 crew members and 227 passengers, disappeared mid-flight between Kuala Lumpur and Beijing in March 2014.

French prosecutors said "with certainty" a piece of wing wreckage found on Reunion Island is from MH370.

Air safety investigators said they had a "high degree of confidence" aeroplane wreckage found on the island of Reunion in July, 2015, is a piece of MH370.

Earlier this week, Thai media speculated a 3m long piece of curved metal which washed up on a beach in Thailand may have come from the missing jet.

The multinational search for the plane has become one of the largest and most expensive in history.

The Fugro Discovery is now returning to Fremantle where a replacement cable will be installed. The spare towfish on board will be readied for future searches.

“Yesterday, while conducting search activities in the southern Indian Ocean, Fugro Discovery lost the sonar vehicle deep tow (towfish) being used to search the ocean floor," the JACC statement said.

“The towfish collided with a mud volcano which rises 2,200 metres from the seafloor resulting in the vehicle’s tow cable breaking. The towfish and 4,500 metres of cable became separated from the vessel and are now resting on the seafloor.”