Partly answering my own question, I found this at
The Times website:
France’s Bureau d'Enquêtes et d'Analyses, BEA, which looks into air crashes, said it made the breakthrough after a further analysis of sonar data gathered during an initial search of the crash area last year when the recorders were still emitting signals. “The BEA was told yesterday ... that the black box recorders have been tracked down by the defence ministry thanks to data from the first phase of the probe, and a further perimeter for searches has been set up,” said a BEA spokeswoman.
The cause of the crash is not known but despite this breakthrough it is unlikely that the boxes will be brought to the surface.
General Christian Baptiste, the deputy defence ministry spokesman, said: “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.”
Two sophisticated salvage vessels, using miniature submarines, have been scouring a 3,000-square-km area to try to locate the flight recorders of the Airbus A330 plane.
Earlier this week, the BEA said it would extend a deep-sea search for the wreck of the plane and that the new search would cover a broader expanse of ocean.
So, it seems that the story is actually telling us nothing about the search work that has been done recently by Seabed Worker. It is merely a re-examination of pinger locator data from last year.
The headline given to the story by the BBC and others is very misleading and suggests a very poor standard of journalism and even worse sub-editing.