An investigation is under way into the life of the co-pilot who has been blamed for causing the French Alps plane crash.

Andreas Lubitz, 27, has been accused of deliberately flying the Airbus A320 into a mountainside shortly after preventing the captain from re-entering the cockpit.

All 150 people aboard the aircraft died in the crash.

Police carrying out searches of Lubitz's flat in Dusseldorf and the home he shared with parents in the historic town of Montabaur have made a "significant find", according to reports.

It was unclear what that find was.

For several hours investigators took away cases and boxes from both addresses. In Dusseldorf police said that they were "looking for clues as to what the co-pilot's motivation might have been".

In Montabaur neighbours reacted with disbelief when the heard of Lubitz's involvement.

One man, who did not want to be named, said that he had known the pilot since childhood.

He told Sky News: "I cannot imagine that he has done it with intention.

"This does not fit in this picture I have of him. It is a very upright family, very helpful and I cannot understand what has happened.

"I knew the children when they were small boys."

Lubitz grew up dreaming of becoming a pilot.

As a teenager he gained his glider's licence after training with LSC Westerwald flying club in his hometown.

Klaus Radke, the chairman of the gliding club, said: "Over the time he was with us he was a very calm, responsible man. 

"Or let me say he was acting responsibly, like many, many others who learn gliding here at our club."

After a period of further training in Arizona, he took a job with Lufthansa in Germany. 

The airline's chief executive said air crew were carefully selected and subjected to psychological vetting.

Despite suggestions that Lubitz may have suffered bouts of depression, there seemed little to suggest that he had been suicidal.

(Sky News)