DNA belonging to 78 people has been found at the scene of the Alps air disaster as investigators continue working at the site.

Recovery teams say they have isolated 78 DNA strands from body parts spread across the crash site of Germanwings flight 4U9525, which went over France on Tuesday killing all 150 on board.

Work is now underway to create a new road to provide better access the scene which can only be got to on foot or by helicopter at the moment.

The route is expected to be completed by Monday night, allowing investigators to continue the search for human remains and parts of the aircraft, including the flight data recorder which is still missing.

The cockpit voice recorder recovered soon after the incident suggests co-pilot Andreas Lubitz crashed the plane deliberately.

A transcript leaked to German media revealed the frenzied final minutes, with the pilot, locked out of the cockpit, shouting "open the damn door!"

The recording, which has not been independently verified, details the captain, who has been named as Patrick Sondenheimer, telling Lubitz he was not able to go to the toilet before take off, to which the co-pilot replies he can go at any time.

The captain then says "you can take over" before Lubitz, 27, refuses to let him back into the cockpit.

Mr Sondenheimer is then heard banging on the door, shouting "for God's sake, open the door".

He then tries to break the door down with an axe as passengers are heard screaming in the background. Investigators believe the next sound is the plane's wing hitting the mountain before final screams.

Meanwhile, reports suggest Lubitz was possibly suffering from a detached retina, while there is also speculation over his mental health after investigators found anti-depressants at his home.

They also found evidence of treatment by various doctors, including a torn-up sick note for the day he flew the plane.

Lubitz's ex-girlfriend has also revealed he vowed last year: "One day I'm going to do something that will change the whole system, and everyone will know my name and remember."

Despite the fears over the co-pilot's mental health, Professor Sir Simon Wessely, president of the Royal College of Psychiatrists (RCPsych), said the aviation industry should not "rush" to action in the wake of the crash.

Sir Simon said: "I have dealt with some pilots with depression and when they recover they are still monitored. But the two I have dealt with returned to very successful careers. Why should they not?

"What does cause trouble is saying that if you ever have a history of depression then you should not be allowed to do whatever. That is wrong."

Civil Aviation Authority documents suggest some 100 commercial airline pilots in the UK had a history of depression, with 42 still on medication.

Meanwhile, there have been calls for a full investigation to be completed before any further conclusions are revealed.

The German Airline Pilots Association pointed out that the flight data recorder was still missing and that the reasons that led to the crash could only be determined once all data had been examined.

The European Cockpit Association said the release of voice recorder data was a "serious breach" of globally accepted rules, adding that many questions remained unanswered.

An official memorial service for those onboard flight 4U9525will be held on April 17 in Cologne Cathedral.

Family members continue to travel to the site of the crash.