The father of the Germanwings pilot who deliberately crashed his aircraft into the Alps killing all 150 people on board has claimed he has new evidence that his son was not to blame for the disaster.

Families of the victims have described the claims made by Günter Lubitz as "traumatic" especially as he plans to reveal fresh evidence on the two-year anniversary of the incident is just days away.

Lubitz is father of co-pilot Andreas Lubitz who, on 24 March 2015, crashed Germanwings Flight 9525 flying from Barcelona to Düsseldorf.

He broke the family's two-year silence on Tuesday (21 March) claiming he had unspecified new evidence that his son was not to blame.

On Friday (24 March), Günter Lubitz plans to present the fresh evidence and said in a statement: "Up to now, everyone believes the theory of a co-pilot who was depressed for a long time, who deliberately crashed his plane into a mountain in a planned act.

"We are convinced this is false."

It has been reported that he had commissioned a report from an aviation journalist who has previously investigated toxic fumes in cabin air on commercial planes.

germanwings plane crash alps
French gendarmes and investigators work among the debris of the Airbus A320 in the French Alps Emmanuel Foudrot/Reuters

The plane began descending rapidly and controllers lost radio contact around 30 minutes into the flight crashing 10 minutes with the wreckage of the aircraft found in the French Alps.

Both French and German authorities launched investigations finding that the 27-year-old deliberately locked the captain out of the cockpit and crashed the aircraft in an act of suicide.

On the plane were 16 German school children returning from an exchange trip with a Spanish school and a seven-month-old baby.

Now relations of the dead victims have condemned the announcement by the Lubitz family which will take place on the exact time of the crash, 10.40am.

Andreas Lubitz Germanwings copilot
Co-pilot Andreas Lubitz had suffered with severe depression before the crash Getty Images

Marlies Weiergräber, who lost her brother and niece in the disaster, told Bild newspaper: "To schedule something like that just as we are remembering our dead loved ones at the memorial in France is traumatic for us,"

"His parents didn't recognise the problem before the crash, but let him continue flying. Now they need help, because they are in denial of the facts. Are they trying to provoke us?" said Klaus Radner, who lost his daughter, her partner and their child.

"For us the first disaster was the crash that killed our loved ones. The second was that some one deliberately caused it to happen. The third disaster is the behaviour of his parents, the provocative display of mourning, the oversized gravestone, and now this press conference."

Andreas Lubitz had a history of depression and in 2008 his training was suspended due to a severe episode and later cleared to fly again.

In January this year, authorities began investigating after a foul smell caused passengers on a Germanwings flight to feel sick shortly after the plane's departure. The flight from Hamburg to Stockholm was forced to land back in Hamburg after the smell was detected on 29 January.