The search for MH370 will continue underwater with experts convinced the Malaysian Airlines flight's black box recorder has run out of battery.
Joint Agency Co-ordination Centre chief Angus Houston says a remote underwater search vehicle will now be deployed in search of MH370.
Joint Agency Co-ordination Centre chief Angus Houston said on Monday no pings had been detected since last Tuesday and it was now time for the next step in the search.
He has also revealed an oil slick had been detected in the search area.
"I can report that (Australian ship) Ocean Shield detected an oil slick yesterday evening in her current search area," Houston said.
A sample has been taken and will be tested when it arrives ashore.
Despite having no new transmissions from the black boxes' locator beacons to go on, air and sea crews were continuing their search in the southern Indian Ocean on Sunday for debris and any sounds that may still be emanating.
They are desperately trying to pinpoint where the Boeing 777 could be amid an enormous patch of deep ocean.
No new electronic pings have been detected since Tuesday by an Australian ship dragging a US Navy device that listens for flight recorder signals.
Recovering the plane's flight data and cockpit voice recorders is essential for investigators to try to figure out what happened to Flight 370, which vanished March 8.
It was carrying 239 people, mostly Chinese, while en route from Kuala Lumpur, Malaysia, to Beijing.
After analysing satellite data, officials believe the plane flew off course for an unknown reason and went down in the southern Indian Ocean off Australia's west coast.
Investigators trying to determine what happened to the plane are focusing on four areas — hijacking, sabotage and personal or psychological problems of those on board.
Two sounds heard a week ago by the Australian ship Ocean Shield, which was towing the ping locator, were determined to be consistent with the signals emitted from the black boxes.
Two more pings were detected in the same general area Tuesday, but no new ones have been picked up since then.
Australian Prime Minister Tony Abbott has expressed confidence that the pings picked up by the Ocean Shield were coming from the plane's two black boxes, but he cautioned that finding the actual aircraft could take a long time.
"There's still a lot more work to be done and I don't want anyone to think that we are certain of success, or that success, should it come, is going to happen in the next week or even month. There's a lot of difficulty and a lot of uncertainty left in this," Abbott said Saturday in Beijing, where he was wrapping up a visit to China.
The underwater search zone is currently a 1300-square-kilometre patch of the seabed, about the size of Los Angeles.
The sub takes six times longer to cover the same area as the ping locator, and will need about six weeks to two months to canvass the current underwater zone. The signals are also coming from 4500 metres below the surface, which is the deepest the sub can dive.
The surface area being searched on Sunday for floating debris was 57,506 square kilometres of ocean extending about 2200 kilometres north-west of Perth. Up to 12 planes and 14 ships were participating in the hunt.