British submarine HMS Tireless has joined the hunt for missing Malaysia Airlines flight MH370 according to a BBC report.
The Ministry of Defence said the Trafalgar class submarine had arrived in the southern Indian Ocean and would help search for the plane’s black box recorder.
It will soon by joined by Royal Navy coastal survey ship HMS Echo.
The aircraft disappeared with 239 people on board on 8 March while en route from Kuala Lumpur to Beijing.
Earlier on Tuesday, Air Chief Marshal Angus Houston – the man co-ordinating the search from Australia – said the hunt was the “most challenging” ever seen and could take weeks.
Several floating objects have been found in recent days, but none is believed to belong to the missing plane.
Nuclear-powered submarine HMS Tireless was launched on 17 March 1984 and holds a crew of 130, plus 18 officers.
An MoD source told the BBC the vessel had “advanced underwater search capabilities, but the task in hand remains a tall order and the search area immense”.
“Her deployment is being co-ordinated closely with our Australian and US colleagues.”
The submarine will listen for ultrasonic “pings” from the plane’s black box, which continue to be broadcast for about 30 days after take-off.
The MoD source said the submarine was ordered to move from an operational tasking to the search area about a week ago and arrived on Monday.
Defence Secretary Philip Hammond informed his Malaysian counterpart of the additional British contribution during a phone call on Tuesday evening.
HMS Echo is expected to begin its work on Wednesday, and the MoD said it would “play an important role in the search for debris on the sea’s surface and her advanced environmental assessment capability will help to optimise search operations”.
Four RAF personnel on secondment to the Royal Australian Air Force and Royal New Zealand Air Force are also actively involved in the search.