Air crash investigators have denied finding the flight recorders of the Air France airliner which came down earlier this month.It follows a report in the French newspaper, Le Monde, which said that signals from the black boxes had been detected. It also claimed a mini-submarine had been launched to locate the recorders that could contain vital information about the crash in which 228 people died. But the French military’s spokesman, Commander Christophe Prazuck, says for the moment nothing suggests the alert picked up comes from a black box. “They haven’t been located or spotted, so the search goes on,” he added. France’s air accident investigation agency, the BEA, has also released a statement saying no signals from the locator beacons have been validated yet. Several countries coordinating the recovery work are now engaged in an urgent race against time. The black boxes emit a signal for a month, meaning searchers only have a week left to find the recorders.