The French navy has located the flight recorders from an Air France jet which crashed in the Atlantic killing 228 people in June 2009 but the black boxes could remain lost on the seabed, a Defence Ministry spokesman said Thursday.

The recorders have been localised "with a margin of error" of three nautical miles (five kilometres), said General Christian Baptiste, the deputy defence ministry spokesman.

And while the news could reassure relatives of the victims still waiting for an explanation of the cause of the disaster, the spokesman said there was no guarantee the recorders would be brought to the surface.

"This does not mean we are going to retrieve the black boxes because they are not giving off a signal any more and the zone where they are is very rugged terrain," Baptiste commented.

The French Navy started a new operation on Monday to find the black boxes.

AFP