The head of Malaysia's air force has denied saying an airliner missing since Saturday had turned back towards Kuala Lumpur, flying hundreds of kilometres to the west.
Malaysia's Berita Harian newspaper had quoted General Tan Sri Rodzali Daud as saying military radar detected the plane near the island of Pulau Perak, at the northern end of the Strait of Malacca, flying about 1,000 metres lower than its previous altitude.
However, Rodzali Daud, the head of the Royal Malaysian Air Force (RMAF), said that in answer to a question from Berita Harian, he had referred the journalist to a statement on March 9, in which he had said the RMAF had not ruled out the possibility the aircraft had turned back before vanishing from the radar.
More than three days after the Boeing 777-200ER disappeared, no trace of the plane or its 239 passengers and crew has been found in waters between Malaysia and Vietnam that have been scoured by more than 40 planes and ships from at least 10 nations.
At the time it lost contact with civilian air traffic control, the plane was roughly midway between Malaysia's east coast town of Kota Bharu and the southern tip of Vietnam, flying at 10,670 metres.
On Monday, Malaysian authorities doubled the search radius to 185km around the point where Malaysia Airlines MH370 disappeared from radar over the South China Sea.
"The biggest problem is just knowing where to look, especially at night," Vo Van Tuan, a top Vietnamese military officer who is leading Vietnam's search effort, told the AFP news agency.
The total search sphere now includes land on the Malaysian peninsula itself, the waters off its west coast, and an area to the north of the Indonesian island of Sumatra.
Police had earlier said they were investigating whether any passengers or crew on the plane had personal or psychological problems that might explain its disappearance, along with the possibility of a hijack.
On Tuesday, Interpol said the disappearance of the plane was not likely to have been caused by a "terrorist" attack.
"The more information we get, the more we are inclined to conclude it was not a terrorist incident," Ronald Noble, head of Interpol told reporters.
However, CIA chief John Brennan said there had been "some claims of responsibility" over the missing jet that had "not been confirmed or corroborated", and that he could not exclude the possibility of a "terrorism" link.