MH370
Families of the missing passengers of the Malaysian Airlines flight MH370 still carry hopes that they are aliveMOHD RASFAN/AFP/Getty Images

The hunt for Malaysia Airlines flight MH370 has hit another speed-bump as the deep-sea sonar vehicle, which was being used to scour the ocean floor for wreckage of the plane, sank after colliding with an underwater volcano.

The "towfish" was scanning the floor of the Indian Ocean when it crashed into a "mud volcano". The Joint Agency Coordination Centre in Canberra released a statement on 25 January saying: "Yesterday [24 January], 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 towfish collided with a mud volcano which rises 2,200 metres from the sea floor 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 sea floor," the statement read.

Fugro Discovery, the search vehicle, will now return to Fremantle, Australia where a new cable will be installed on it. "There were no injuries to crew and it is believed it will be possible to recover the towfish at a later date."

Earlier this month, another search vehicle Havila Harmony stumbled upon a 200-year-old ship wreck during the search for the missing Malaysia Airlines flight MH370. The plane disappeared during a routine flight from Kuala Lumpur to Beijing on 8 March, 2014 with 239 people on board.

The disappearance of the flight has been surrounded by controversy from the start with many suggesting that the whole incident was part of a terrorist hijacking plot. On 23 January, a piece of plane wreckage washed up along the southern coast of Thailand which drew fresh conjecture that it might belong to the MH370.

Local authorities said that going by the growth of barnacles on the wreckage, the aircraft piece must have sunk approximately a year ago. However, on examining the debris, aviation experts said that it was very unlikely that the piece was part of the Malaysian plane and "would appear to be inconsistent with the drift models that appeared when MH370's flaperon was discovered in Reunion last July," said Greg Waldron, Asia Managing Editor at Flightglobal, an industry publication.

"The markings, engineering, and tooling apparent in this debris strongly suggest that it is aerospace related," said Waldron. "It will need to be carefully examined, however, to determine its exact origin."

In July last year, the flaperon washed up on a beach in the French, Reunion Island and it was confirmed that it was that of the Malaysia Airlines flight. As families of the missing passengers still to hope that the flight was diverted and that all passengers are still alive, Australian authorities continue to search the Indian Ocean for the wreckage of the plane.

The country's Deputy Prime Minister Warren Truss has however said that the search might have to be called off by June, since most of the designated search zones have already been examined.