The co-pilot of the crashed Germanwings plane, Andreas Lubitz, had received treatment for suicidal tendencies before getting his pilot licence, investigators say, but not recently.

Lubitz, 27, is suspected of deliberately crashing the plane in the Alps, killing all 150 people on board. Officials in Duesseldorf said the investigation to this point had revealed no clue to any motive. So far, DNA strands of 80 of the victims have been found.