A French official says sounds detected by search teams in the Atlantic depths are not those of Flight 447's black boxes. The aide to France's top transport official, Jean-Louis Borloo, said Tuesday the "black boxes have not been detected." She said that French military ships searching in the area where the plane crashed have "heard sounds" but that those were not signals from the flight's voice or data recorders. Le Monde had reported earlier that the French military has detected a faint signal from the black boxes of the plane, which crashed in the Atlantic in late May. The report says that, with eight days to go until their power dies, a "very weak signal" from the flight recorders was received by French ships. In light of this, a mini research submarine, the Nautile, dived Monday to search for the boxes. The recorders' signal has a range of approximately 2 kilometers, but the ocean floor at the crash zone is deeper than that. The report on Le Monde's Web site Tuesday gives no source or other details. It is not clear whether the signal came from the flight's data recorder or the voice recorder. Officials with the French military and the French marine institute that operates the mini-sub, Ifremer, could not immediately be reached for comment on the report. French air accident investigators and Air France officials did not immediately respond to phone calls. Brazilian and American officials said that as of Sunday evening no signals from the black boxes had been picked up. All 228 passengers on the plane, an Airbus A330, were killed May 31 when it crashed while en ruote from Rio de Janeiro to Paris. The causes of the crash remain unclear, and investigators hope that the black boxes may shed some light on the accident. No messages of distress were broadcast by the crew prior to the crash, although an automatic message sent by the plane just before it disappeared reported loss of pressure and failure of electric systems. Searchers from Brazil, France, the United States and other countries are methodically scanning the surface and depths of the Atlantic for signs of the plane. French-chartered ships are trolling a search area with a radius of 80 kilometers, pulling US Navy underwater listening devices attached to 6,000 meters of cable. Ten of 50 bodies recovered from the Air France flight that plunged into the Atlantic three weeks ago have been identified as Brazilians, medical examiners said. Dental records, fingerprints and DNA samples were used to identify the bodies. Investigators are reviewing all remains, debris and baggage at a base set up in Recife, Brazil.