The evidence came from the search of the 28-year-old’s homes in two German cities for an explanation why he crashed the Airbus A320 into the French Alps, killing all 150 people on board.

Martyn Matthews, a quality manager at Tipton-based automotive firm Huf UK, was one of those on board.

Mr Matthews had been in Barcelona for business, and only caught the doomed flight in order to get home to his Wolverhampton-based family sooner.

Colleagues at Huf, which makes car components, said the 50-year-old was a ‘really nice man’.

The head of Lufthansa, Germanwings parent company, admitted Lubitz had taken a long break from pilot training, while German media reported he had been battling mental health issues.

Prosecutor’s spokesman Ralf Herrenbrueck said torn-up sick notes for the day of the crash “support the current preliminary assessment that the deceased hid his illness from his employer and colleagues”.

Such sick notes from doctors excusing employees from work are common in Germany and issued even for minor illnesses. Mr Herrenbrueck did not reveal details of what illness Lubitz was suffering from.

He said other medical documents found indicated “an existing illness and appropriate medical treatment”, but that no suicide note was found. He added there was no indication of any political or religious motivation for Lubitz’s actions.

Germanwings, a subsidiary of Lufthansa, refused to comment on the new information.

Investigators had removed multiple boxes of items from Lubitz’s apartment in Dusseldorf and his parents’ house in Montabaur, near Frankfurt.

A German aviation official said Lubitz’s file at the country’s Federal Aviation Office contained an “SIC” note, meaning he needed “specific regular medical examination”. Such a note could refer to either a physical or mental condition, but the official said the note does not specify which.

However, neighbours described a man whose physical health was superb.

“He definitely did not smoke. He really took care of himself. He always went jogging. I am not sure whether he did marathons, but he was very healthy,” said Johannes Rossmann, who lived a few doors down from Lubitz’s home in Montabaur.

German news media painted a picture of a man with a history of depression who had received psychological treatment, and who might have been set off by a falling-out with his girlfriend. Dusseldorf prosecutors, who are leading the German side of the probe, refused to comment on the anonymously sourced reports, citing the continuing investigation.

Lufthansa chief executive Carsten Spohr said there was a “several-month” gap in Lubitz’s training six years ago, but would not elaborate. Following the disruption, he said, Lubitz “not only passed all medical tests but also his flight training, all flying tests and checks”.

The US Federal Aviation Administration had issued Lubitz a third-class medical certificate. To obtain a certificate, a pilot must be cleared of psychological problems including psychosis, bipolar disorder and personality disorder “severe enough to have repeatedly manifested itself by overt acts”.

The certificate also means he was not found to be suffering from another mental health condition that “makes the person unable to safely perform the duties or exercise the privileges” of a pilot’s licence.

French investigators, who are in charge of the probe into the plane crash, believe the 27-year-old locked himself inside the cockpit and intentionally smashed the Germanwings plane into a mountainside on Tuesday during a flight from Barcelona to Dusseldorf.

People in Montabaur who knew Lubitz said they were shocked at the allegations that he could have intentionally crashed the plane, saying he had been thrilled with his job at Germanwings and seemed to be “very happy”.

Germanwings, a low-cost carrier in the Lufthansa Group, said it was setting up a family assistance centre in Marseille for relatives of those killed in the crash.

“In these dark hours our full attention belongs to the emotional support of the relatives and friends of the victims of Flight 9525,” Germanwings chief executive Thomas Winkelmann said.