FILE - In this March 24, 2014 file photo, co-pilot, flying officer Marc Smith turns his Royal Australian Air Force AP-3C Orion aircraft at low level in bad weather whilst searching for missing Malaysia Airlines Flight 370 over the Indian Ocean.
A US Navy spokesman on Thursday dismissed as "speculative and premature" an American expert's reported comments that the acoustic "pings" at the centre of the search for the missing Malaysian plane had not come from the jet's black boxes.
CNN reported the Navy's deputy director of ocean engineering, Michael Dean, had said most countries now agreed that the sounds detected by the Navy's Towed Ping Locator in April in the southern Indian Ocean came from a man-made source unrelated to the missing jet.
"Mike Dean's comments today were speculative and premature, as we continue to work with our partners to more thoroughly understand the data acquired by the Towed Pinger Locator," US Navy spokesman Chris Johnson said in a statement.
The Navy would defer to Australia, as the lead in the Indian Ocean search effort, to make additional information known at the appropriate time, Johnson said.
Australia's Joint Agency Coordination Center did not immediately respond to requests for comment to the report on Thursday. Dean could not be immediately reached for comment.
Australian Transport Minister Warren Truss also did not immediately respond to a request for comment.
Malaysia Airlines Flight 370 vanished with 239 people on board on March 8 during a flight from Kuala Lumpur to Beijing. Satellite analysis led authorities to believe that the Boeing 777 had diverted sharply from its flight path and flown south to the Indian Ocean. Officials have described the detection of four series of "pings" as their best lead in the search for the jet's black box.
But an intensive search by an unmanned submarine has found nothing so far.