Agence France-Presse now saying "hold it" on débris.
15:30 (Paris time): "French army spokesmen, based at Dakar (Sénégal) and co-ordinating the search for the missing A330, have explained that they have found nothing for the moment; that the weather is atrocious; and that they are not in a position to confirm the findings of the Brazilian military, which claims to have seen 'small pieces of débris' near the Fernando de Noronha archipelago."
The Dutch news agency BNO is saying that an aircraft seat was seen floating 720 km away from the same island (not 650 km as previously reported), so there does seem to be some confusion as to precisely what has been observed where.