The French government says debris discovered in the waters off Brazil is trash and not the wreckage of Air France flight 447. But Brazilian officials disagree.
There are now concerns about whether investigators are even looking in the right place for the doomed jet.
France's transportation minister, Dominique Bussereau, said Friday that French forces have found no evidence of the Airbus A330 airplane that vanished over the Atlantic Sunday night with 228 people aboard.
But Brazilian officials continue to insist that military pilots have spotted scattered wreckage from the flight across the ocean's surface.
On Friday, Airbus said that French authorities have said that the flight was receiving inconsistent airspeed readings from multiple instruments as it dealt with severe turbulence amid a thunderstorm.
Brazil Air Force Brig.-Gen. Ramon Cardoso again expressed confidence that at least some of the objects spotted -- an airplane seat, a slick of fuel and other pieces -- are from the doomed jet.
"This is the material that we've seen that really was part of the plane," Cardoso said.
Little of the debris has been recovered since ships in the search area have been hampered by poor visibility and rough waters. The only piece that was picked up, a cargo pallet, turned out to be sea garbage.
"There is a lot of garbage in the sea, and sometimes what might seem to be wreckage is actually trash," said Brazilian Navy Adm. Edson Lawrence.
Bussereau said he regretted the announcement by Brazilian teams that they had recovered wreckage from the flight.
"French authorities have been saying for several days that we have to be extremely prudent," Bussereau told France's RTL radio. "Our planes and naval ships have seen nothing."
"We would have preferred that it (the debris) had come from the plane and that we had some information," Bussereau added.
He noted the search must continue and stressed the priority is finding the flight recorders.
France is sending a nuclear submarine to assist in the search.
An Air France memo says the company will replace the instruments, known as Pitot tubes in "coming weeks." The memo does not say when the process started and did not comment on the memo to media.
The Pitot tubes extend from the wing and fuselage of a plane and are heated to prevent icing. They measure the speed and the angle of the flight.
An iced over Pitot tube could cause an airspeed sensor to fail, a factor investigators are considering.
Airbus has sent an advisory to all operators of the A330 warning crews to follow standard procedures if they suspect speed indicators are faulty.
Airbus spokesman Justin Dubon said the plane maker sent the bulletin after BEA, the French agency investigating the crash, said the jet had faced turbulent weather and inconsistency in the speed readings by different instruments.
That meant "the air speed of the aircraft was unclear," Dubon said. In such circumstances, flight crews should maintain thrust and pitch and level off the plane and start troubleshooting procedures, Dubon said.
The Air France flight was en route from Rio de Janeiro to Paris when it hit turbulence early Monday and presumably plunged into the Atlantic.
The aircraft issued a final batch of automated messages over a three minute period, right before it left radar, indicating inconsistencies between the different measured airspeeds, shortly after the plane entered a storm zone.
Airbus said its message to clients did not imply that the doomed pilots did anything wrong or that a design fault was in any way responsible for the crash.
"This Aircraft Information Telex is an information document that in no way implicates any blame," said Dubon.
Such warnings are customarily sent only if accident investigators have established facts that they consider important enough to pass on immediately to airlines.
More than 300 aircraft similar to the missing Air France jet are in service worldwide.
