SYDNEY, May 30 -- An Australian deep sea expert said on Friday that finding flight MH370 will be "virtually impossible" without new clues.

After three months of searching, Malaysia Airlines flight with 239 people on board is still missing and is believed to be somewhere on the bottom of the Indian Ocean off the coast of Australia.

On Thursday, authorities stopped searching in an area where acoustic pings had been detected. It was earlier believed the pings may have been coming from the aircraft's black box, however this proved to be a dead end.

Authorities have now turned to a massive 60,000 sq km arc of the southern Indian Ocean.

A Sydney-based oceanographer told news.com.au that finding the plane in this huge area was "virtually impossible" unless there was a new lead.

Erik van Sebille from the University of NSW, who is an expert on the oceans surrounding Australia, said underwater searches were incredibly difficult.

"It's virtually impossible to find the plane if there's not an extra lead," Dr. van Sebille said.

"If there's no other lead .. then I think we are in a pretty dire situation."

A Chinese survey vessel has begun mapping the ocean floor, which is considered the next best hope of finding the plane.

Dr. van Sebille said only about 5 percent of this part of the sea floor terrain had been mapped before and that man had better maps of the surface of Mars.

"The chances of spotting the plane itself are very, very slim this way," he said. "It's quite unlikely."

A spokesperson for Infrastructure Minister Warren Truss said 89. 9 million Australian dollars (83.74 million U.S. dollars) had been allocated in the Federal Budget up to next June in funding the ongoing search.

"The Australian Government is committed to the search for MH370 and understands the importance of trying to resolve the mystery for the sake of the families and friends of those who have been lost," the spokesperson said.