The search for missing Malaysia Airlines flight MH370 is returning to an area off Perth that was first searched three months ago.

Australian Transport Safety Bureau (ATSB) chief commissioner Martin Dolan said new data showed the area of highest probability of where the plane crashed into the Indian Ocean was 1,800 kilometres west of Perth.

Only aerial searches of the area were conducted in late March before the search moved further north.

Flight MH370, carrying 239 crew and passengers, including six Australians, disappeared from radar screens on March 8 shortly after taking off from Kuala Lumpur bound for Beijing.

The new search zone comes as Dutch engineers begin a survey to map uncharted deep sea terrain at the bottom of the Indian Ocean in search of the plane.

A survey ship from Dutch engineering company Fugro, carrying 40 crew and technicians, began mapping out an area larger than the Netherlands, some 1,600 kilometres off the West Australian coast.

The search for the lost plane is being coordinated by the ATSB, and is expected to cost $60 million in the first year.

Fugro usually conducts surveys of ocean floors for oil and telecommunications companies.

Strategy director Rob Luijnenburg says this search area is in a particularly rough location.

"The area has mountains, ridges, valleys, and you can't see a lot down there unless you make it visible with technology," he said.

"For the first phase you need a good map, once you have that you can plan the next phase."

It will take roughly three months for the Fugro Equator survey ship, which is being assisted by a Chinese naval vessel, to map the topography of the ocean floor.

Once an accurate map has been constructed with the aid of computers on board the ship, searchers can begin more detailed and slower surveys in a bid to find the plane itself, using unmanned robots and submarines to search the ocean floor.

Area to be mapped is 6,000 metres deep

Investigators say what little evidence they have to work with, including the loss of communications, suggests the Boeing 777 was deliberately diverted thousands of kilometres from its scheduled route.

The area being mapped is largely uncharted. Mr Luijnenburg said the area's remoteness and depth at 6,000 metres placed it beyond the reach of the oil industry, which is still pushing down to depths approaching 3,000 metres.

With a long maritime history and seafaring expertise, Dutch companies are leaders in the field of complex, large-scale undersea search and salvage operations.

Wrecks on which Dutch companies have worked include the raising of the Russian nuclear submarine Kursk, which sank in the depths of the Barents Sea in 2000 with the loss of all on board.

More recently, Dutch firms were contracted to help salvage the Costa Concordia cruise liner, which sank off the coast of Italy in 2012.

Fugro's ship will use an echo sounder for the topographic mapping stage to build up a relatively low-resolution picture of the entire area as quickly as possible. Its crew will stay at sea for a month at a time.

"It's extremely unlikely that we will be able to pick up something the size of an aircraft and make it out to be that at this stage," Mr Luijnenburg said.

ABC/Reuters