Germanwings Airbus
Germanwings Airbus Reuters

French aviation experts argued Thursday that the black box recordings of the Germanwings aircraft that crashed Tuesday in the French Alps increase suspicion that one of the pilots intentionally downed the flight. 

According to the experts, "it was a deliberate action of a member of the flight crew" - potentially a suicide. 

The New York Times reported earlier Thursday that one of the pilots onboard had been locked out of the cockpit when the plane descended. 

Evidence from the cockpit voice recorder, a senior military official involved in the investigation related, indicated that one of the pilots had left the cockpit in the middle of the flight and could not re-enter. 

"The guy outside is knocking lightly on the door, and there is no answer. And then he hits the door stronger, and no answer. There is never an answer," the investigator said. 

"You can hear he is trying to smash the door down," the investigator noted, adding that no response from the other side of the cockpit is heard on the recording. 

While the audio provided some insight into the reasons for the crash, questions remain unanswered. 

"We don't know yet the reason why one the guys went out. But what is sure is that at the very end of the flight, the other pilot is alone and does not open the door."

All 144 passengers as well as the flight's six crew members were killed in the crash. Eyal Baum, a 39-year-old Israeli businessman who was living in Barcelona, was among those who perished in the disaster.