Andreas Lubitz
Andreas LubitzReuters

Lufthansa has admitted that it was in fact aware that Germanwings copilot Andreas Lubitz, who purposely crashed his plane in the French Alps killing all 149 others aboard, was suffering from a severe mental illness - but that it allowed him to fly nonetheless.

According to the company, which owns Germanwings, in 2009 Lubitz contacted his flying school to alert them of "a previous episode of mental depression."

The astonishing admission represents an embarrassing climbdown from claims by Lufthansa CEO Carsten Spoh that the 27-year-old German had been cleared as "100 percent fit to fly without caveats", as the company rushed to avoid responsibility in the immediate aftermath of Lubitz's murderous act.

Skepticism over the company's claims that it didn't know about Lubitz's mental health problems surfaced near the start of the investigation, when prosecutors found several torn-up sick notes in his house. At the time, however, it was claimed he had hidden the evidence from his employers.

On Monday, investigators revealed he had received treatment for "suicidal tendencies."

The revelations come as disturbing video footage taken by a passenger shows the final moments before the crash. Passengers can be heard screaming and shouting "my God!" in several languages as they realized what was about to happen.

The French magazine Paris Match and German daily Bild both reported of having seen the video, which was recorded on a cell phone, and say it is of "unquestionable" authenticity having been found amid the debris of the crash.