Markus Niesczery from Dusseldorf Police told the Daily Mail: "We have found something which will now be taken for tests. We cannot say what it is at the moment but it may be a very significant clue to what has happened. We hope it may give some explanations." Deep crisis: Co-pilot Andreas Lubitz. Credit:Facebook German detectives were also pictured carrying evidence from another property - a $750,000 home in Montabaur, a town 65 kilometres from Bonn, that the pilot is believed to have shared with his parents. Police were seen leaving with large blue bags of evidence and a computer. A man, thought to have been his housemate, was led out of the building, shielded by police holding up jackets. The 27-year-old is understood to have split his time between the two addresses.

Lubitz barricaded himself alone in the cockpit of Germanwings flight 9525 and apparently set it on course to crash into an Alpine mountain, killing all 150 people on board including himself, French prosecutors said on Thursday. Police outside the home of the parents of Andreas Lubitz. Credit:Getty Images They offered no motive for why he would have taken the controls of the Airbus A320, locked the captain out of the cockpit and deliberately set it veering down from cruising altitude at 3000 feet a minute. German police searched his home for evidence that might offer some explanation. German police officers carry bags of evidence out of a house in Montabaur that belongs to the parents of crashed Germanwings co-pilot Andreas Lubitz. Credit:Reuters

The scenario stunned the aviation world. Within hours of the prosecutors' announcement, several airlines responded by immediately changing their rules to require a second crew member to be in the cockpit at all times. That is already compulsory in the United States. Lubitz acted "for a reason we cannot fathom right now but which looks like intent to destroy this aircraft", Marseille prosecutor Brice Robin said. Setting the plane's controls for rapid descent was an act that "could only have been voluntary", Mr Robin said. "He had ... no reason to stop the pilot-in-command from coming back into the cockpit. He had no reason to refuse to answer to the air controller who was alerting him on the loss of altitude." The captain, who had stepped out of the cockpit, probably to use the toilet, could be heard on flight recordings trying to force his way back in.

"You can hear banging to try to smash the door down," Mr Robin said. Most of the passengers would not have been aware of their fate until the very end, he said. "Only towards the end do you hear screams," he said. "And bear in mind that death would have been instantaneous ... the aircraft was literally smashed to bits." FlightRadar24, an online air tracking service that uses satellite data, said it had found evidence the autopilot was abruptly switched from cruising altitude from 38,000 feet to just 100 feet, the lowest possible setting. The plane crashed at about 6000 feet. Lufthansa chief executive Carsten Spohr said its air crew were picked carefully and subjected to psychological vetting.

"No matter your safety regulations, no matter how high you set the bar, and we have incredibly high standards, there is no way to rule out such an event," Mr Spohr said. Attention was focused on the motivations of Lubitz, a German national who joined the Lufthansa-owned budget carrier in September 2013 and had just 630 hours of flying time - compared with the 6000 hours of the flight captain. "Suicide" was the wrong word to describe actions which killed so many other people, Mr Robin said. "I don't necessarily call it suicide when you have responsibility for 100 or so lives." The family of the co-pilot arrived in France for a tribute alongside other victims' families. They were being kept apart from the others, Mr Robin said.

Telegraph, London