Multinational search operations for the Malaysian airliner that went missing March 8 remained futile for the 10th day Monday even as the carrier said that initial investigation revealed that it was the co-pilot who spoke the last words before the plane disappeared.
"We are now changing our focus to the central eastern Indian Ocean to try to solve this mystery," he said.
Australia has provided two RAAF P-3C Orion aircraft to assist the Malaysian government in its search since March 9.
Malaysia Airlines MH370 with 239 passengers and crew on board vanished mysteriously about an hour after taking off from Kuala Lumpur early March 8.
The Boeing 777-200ER was initially presumed to have crashed off the Vietnamese coast in the South China Sea.
The plane was due to land in Beijing at 6.30 a.m. the same day. The 227 passengers included five Indians, 154 Chinese and 38 Malaysians.
Contact with the plane was lost along with its radar signal at 1.40 a.m. March 8 when it was flying over the air traffic control area of Ho Chi Minh City.
Johnston confirmed Australian aircraft were being directed by the Royal Malaysian Air Force commander for the western region search area and information on the search would be directed to the Malaysian authorities.
One RAAF P-3C Orion started searching in the Indian Ocean to the north and west of the Cocos Islands and the other would continue to search west of Malaysia.
France, which experienced its own search for a missing plane when an Air France flight disappeared off the coast of Brazil in 2009, has also confirmed its assistance, with the assignment of four experts.
India has supported search operations in the Andaman Sea and Bay of Bengal but this was suspended Sunday at the request of Kuala Lumpur.
The Indian defence ministry said the search would remain suspended until notice by Malaysia on which areas to search.
Malaysian Prime Minister Razak Sunday hinted at foul play, saying someone probably deliberately diverted the plane from its flight path.
Malaysia Airlines said in a press conference Monday that the initial investigation revealed that it was the co-pilot of the missing plane who spoke the last words before flight MH370 disappeared.
"Initial investigations indicate it was the co-pilot who basically spoke," Ahmad Jauhari Yahya. chief executive officer of malaysia Airlines, said. "All right, good night" was reportedly the last words from the missing plane.
He said the last transmission from the aircraft commuication and reporting system (ACARS) was at 1.07 a.m. March 8, but it was unknown when it was switched off. It was supposed to transmit 30 minutes later as programmed, which it did not.
He also said that psychological and psycho-motor tests were standard procedures for pilot recruitment.
He said so far they had received no evidence from any telecommunication companies suggesting any passenger on the missing plane tried to make phone calls.
Answering questions from a reporter, acting Malaysian Transport Minister Hishammuddin Hussein said they were investigating into the personal and financial problems of the pilot and co-pilot.
He also said Malaysian authorities had cooperated with the FBI and the Interpol since the first day of the incident.