Canberra - The seabed search for the missing Malaysia Airlines jet is set to widen as a sonar scan of the most likely crash site deep beneath the Indian Ocean nears completion without yielding a single clue, authorities said on Friday.
The Australian search co-ordination centre said a robotic submarine had scanned 95% of a 310-square-kilometer search area since last week but had found nothing of interest.
The US Navy's Bluefin 21 is creating a three-dimensional sonar map of the ocean floor near where signals consistent with airplane black boxes were heard on 8 April.
The search area is a circle with a 10km radius 4.5km deep off the west Australian coast. The search of the target area is scheduled to be completed within days.
"If no contacts of interest are made, Bluefin 21 will continue to examine the areas adjacent to the 10-kilometer radius," the centre said in a statement.
"We are currently consulting very closely with our international partners on the best way to continue the search into the future," it added, referring to Malaysia, United States and China.
Malaysian Prime Minister Najib Razak told CNN on Thursday that his government will release a preliminary report on the plane's disappearance next week.
The report has already been sent to the United Nation's International Civil Aviation Organisation, but has yet to be made available to the public, CNN reported.
Australian Defence Minister David Johnston said this week that an announcement was likely next week on the next phase of the search for the Boeing 777 which vanished with 239 passengers and crew on board on 8 March during a flight from Kuala Lumpur to Beijing.
He said the next phase was likely to deploy more powerful side-scan sonar equipment that can delve deeper than the Bluefin 21.
On Friday, up to 8 planes and 10 ships were to search for debris over a 49 000 square kilometre ocean expanse 1 600km northwest of the city of Perth where the search is headquartered, the centre said.