The New York Times also reported that antidepressants were found during the search of his apartment. CNN has not been able to confirm the reports.
French authorities have said that Lubitz appeared to have deliberately crashed Germanwings Flight 9525 into the Alps on Tuesday as it flew from Barcelona toward Dusseldorf, Germany, with 150 people on board.
`Unfit to work`
Investigators continued to work Saturday to piece together the secret life of Lubitz, who officials say was hiding an illness from his employers. He had been declared "unfit to work" by a doctor.
They were expected to question his relatives, friends and co-workers as they try to pin down what could have prompted the seemingly competent and stable co-pilot to steer a jetliner full of people into a mountainside.
As their efforts continued, dozens of people attended a remembrance ceremony for the victims of the crash at a church in a nearby town, Digne-les-Bains. Most of the people on the plane were from Germany and Spain.
Relatives of the victims and local residents also gathered Saturday afternoon by a simple stone memorial set up near the crash site, in the village of Le Vernet. Flowers have been laid there, in the shadow of the snow-covered peaks of the French Alps.
Mental health speculation
Much attention has focused on Lubitz`s state of mind, with suggestions that he may have had mental health issues.
Investigators found a letter in the waste bin of his Dusseldorf, Germany, apartment saying that Lubitz, 27, wasn`t fit to do his job, city prosecutor Christoph Kumpa said Friday. The note, Kumpa said, had been "slashed."
Just what was ailing Lubitz hasn`t been revealed. The New York Times and the Wall Street Journal, citing unnamed sources, reported Friday that Lubitz suffered from mental illness and kept his diagnosis concealed from his employer.
A subsequent New York Times report on Saturday, citing two officials with knowledge of the investigation, said Lubitz sought treatment before the crash for vision problems that might have put his career at risk.
According to those unnamed officials, Lubitz also was being treated for psychological issues. Other media reports indicate he was treated for depression.
Ripped up medical notes
Lubitz passed his annual pilot recertification medical examination in summer 2014, a German aviation source told CNN.
An official with Lufthansa, which owns Germanwings, said that the exam only tests physical health, not psychological health, and that if Lubitz had vision problems, that would have been discovered during the tests.
The official also said that the company was never given any indication Lubitz was depressed, and that if he went to a doctor on his own, he would have been required to self-report if deemed unfit to fly.
A Dusseldorf clinic said he`d gone there twice, most recently on March 10, "concerning a diagnosis." But the University Clinic said it had not treated Lubitz for depression.
German investigators said they still have interviews and other work to do before they can reveal what they gleaned from the records found in the apartment and at his parents` home in the town of Montabaur.
But the fact that investigators found "ripped, recent medical leave notes, including for the day of the offense, leads to the preliminary conclusion that the deceased kept his illness secret from his employer and his professional environment," prosecutors said.
Germanwings corroborated that assertion, saying it had never received a sick note from Lubitz.
No scenario ruled out
Jean Pierre Michel, lead investigator for the French inquiry, said on Saturday that he could not yet address reports of Lubitz`s possible mental illness.
But Michel also said investigators weren`t ruling any scenario out at this point.
Lubitz is believed to have locked the pilot of Flight 9525 out of the cockpit before putting the plane on a rapid descent into the mountains, French authorities have said.
Although search teams have recovered the cockpit voice recorder, the flight data recorder remains missing. That device could reveal crucial details about what happened during the final moments of the flight.
More about: