Authorities say the co-pilot involved in this week’s Germanwings crash hid evidence of an illness from the airline.

Officials say Andreas Lubitz tore up various sick notes from his doctor, including one that would have excused him from work the day of the crash. Authorities found these notes at Lubitz’s apartment and at his parents’ home.

Germanwings confirmed to Fox News that it did not receive any of the notes.

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University Hospital Dusseldorf confirmed that Lubitz was treated there over the last two months and that he was seen as recently as March 10. They would not confirm what he was being treated for but said it was not depression.

Investigators did not find a suicide note or confession during their searches.

Authorities say Lubitz deliberately crashed the plane into the French Alps, killing 150 people on board.