The co-pilot suspected of crashing a German airliner into the French Alps, killing himself and 149 others, knew the region from gliding holidays.

A member of the Montabaur flight school where Andreas Lubitz took lessons confirmed to BBC News the co-pilot had flown a glider over the region.

Lubitz was on holiday at the time, several years ago, Dieter Wagner said.

A French newspaper reports that the co-pilot holidayed at a local flying club with his parents from the age of nine.

Investigators are trying to establish what may have motivated Lubitz to seize sole control of the Airbus A320 and crash it.

German prosecutors believe he was concealing an illness from his employer, Germanwings, at the time of the crash.

Data from the voice recorder suggests the 27-year-old purposely started an eight-minute descent into the mountains after locking the pilot out of the flight deck.

There were no survivors when Flight 4U 9525 crashed in a remote Alpine valley on Tuesday while en route from Barcelona in Spain to Duesseldorf in Germany.

Prosecutors say there was no evidence of a political or religious motive for his actions and no suicide note has been found.

'Obsessed' with the Alps

Lubitz flew a glider over the southern French Alps during a holiday with the flight school in Montabaur, his home town, Dieter Wagner told the BBC.

He had been holidaying there before he became a professional airline pilot.

Wagner, who says he last saw the young man five or six years ago, was quoted by French newspaper Le Parisien (in French) as saying the co-pilot had been "passionate about the Alps and even obsessed with them".

Another French news outlet, Metro News, reports that Mr Lubitz holidayed with his parents from the age of nine at the flying club in Sisteron, 69km (43 miles) from Le Vernet, a village near the crash site.

Quoting a "friend of his parents", the paper said in its reports (in French) the family had stayed at a nearby campsite and Andreas had come across as a "normal boy".

Metro News quoted Francis Keser, a designer at the club in Sisteron, as saying Lubitz had "known the area well".

Lubitz's health timeline

--2009: Breaks off pilot training while still in his early twenties after suffering "depressions and anxiety attacks", the German tabloid Bild reports, quoting Lufthansa medical files. Resumes training after 18 months of treatment, according to Bild

--2013: Qualifies "with flying colours" as pilot, according to Lufthansa

--2013-2015: Medical file quoted by Bild marks him as requiring "specific regular medical examination" but no details are given

--February 2015: Undergoes diagnosis at Duesseldorf University Clinic for an unspecified illness; clinic has clarified the illness was not depression

--10 March 2015: Again attends Duesseldorf University Clinic

--24 March 2015:Is believed to have deliberately crashed airliner, killing himself and 149 others

--26 March 2015: Prosecutors announce that two sick notes have been found torn up at his addresses in Germany