Malaysia's acting Transport Minister Hishammuddin Hussein Sunday said key communications equipment that keeps the ground updated about the condition of an aircraft and its engines while flying was disabled on the Boeing 777-200 before the last recorded cockpit conversation.
The missing plane and its 227 passengers and 12 crew disappeared March 8 on a flight from Kuala Lumpur to Beijing.
"Yes, it was before," Hishammuddin said when asked about whether the Aircraft Communications Addressing and Reporting System was disabled before someone said, "All right, good night" from the cockpit.
On Monday, however, Ahmad Jauhari Yahya, chief executive officer of Malaysia Airlines, said the ACARS was working normally just before the last words were heard but failed to send its next scheduled signal about 30 minutes later, the New York Times reported. He said the plane's first officer was the last person to talk to air traffic controllers.
"We don't know when the ACARS system was switched off," he said.
Hishammuddin, who was standing beside Jauhari, said, "What I said yesterday was based on fact, corroborated and verified" and that the uncertainty about the chronology underscored the importance of finding the aircraft and its data recorders.
More than two dozen countries have sent ships and planes to help search for debris more than 3,200 miles away from the point at which officials believe the plane's transponders and another signaling system were deliberately turned off about an hour into the flight, the Wall Street Journal said.
Malaysian authorities now say they suspect foul play was behind the plane's disappearance and were investigating all crewmembers and passengers on the flight. Police, who searched the pilots' homes during the weekend, taking a computerized flight simulator from the home of the plane's captain, and said nothing so far linked the pilots to the plane's disappearance.
Satellite tracking suggested the plane likely traveled for hours and was on one of two possible routes: one from northern Thailand to the border of Kazakhstan and Turkmenistan or one from Indonesia to the southern Indian Ocean.
"At this stage, both the northern and southern corridors are being treated with equal importance," Hishammuddin, who is also the Malaysian defense minister, said.