Brad Pitt clashed with his eldest son Maddox during a flight last week.
The 52-year-old actor is reportedly being investigated by the FBI over claims he had verbally and physically abused one of his children while drunk on a private jet, an incident which led his wife Angelina Jolie to file for divorce, and it has now emerged he had got into a lengthy row with the teenager before they even boarded the plane in France.
A long-time member of staff told The Sun newspaper: "There was a disagreement with the eldest boy.
"I know it started on the way to the airport before the plane took off and escalated on the plane.
"It was a teenage thing, there is a lot of hormones going on.
"They were gone for over 10 days.
"You put eight people in a little tube like that and put them up in the air for 121/2 hours, add this and that to it."
But another member of staff insisted there was no evidence of "abuse".
Another current member of staff added: "I was there for pick-up at the end of the night.
"Obviously things were tense.
"There were definitely some hurt feelings but I have never seen any evidence of abuse or anything like that."
Brad is said to be "distraught and terrified" because he has not been able to see Maddox or his siblings, Pax, 12, Zahara, 11, Shiloh, 10, and eight-year-old twins Knox and Vivienne, since the row.
A source said: "He takes the investigation very seriously and he is cooperating fully.
"He was not physical in the way that has been reported.
"He will always do whatever is best for his kids."
And one of the staff members added: "I have never seen Brad like this. He is distraught, pacing, nervous - totally terrified.
"He is just expressing to me that he is scared. He is scared of losing his kids over something that he hasn't done and him being made out to look like a bad father. He is far from a bad father.
"He's not able to see the kids at the moment but he is constantly in touch with staff asking to make sure they're OK.
"He keeps saying: 'Just look after my kids, that's all that matters right now.'"
And the second staff member insisted the 'Fight Club' actor is a "kind and nice" father, though the one who "enforces" discipline in the household.
He said: "He is kind and really nice with the kids.
"Brad is an easy-going guy, not aggressive.
"He is not mean.
"I'm sure he's human from time to time. I've heard a bit of arguing to that extent, but nothing severe, no pattern of being cruel or mean.
"He is a good father. If there was something where someone would pick out a belt - I have never seen anything like that.
"And I have been in close proximity inside those homes...
"He is a dad who will want the kids to do chores and things like that. Like most mums and dads, it's good cop bad cop thing. Like the old saying, 'Wait until your father gets home'. Brad is kind of the enforcer. The kids never complained."
Angelina, 41, filed for divorce on Monday (19.09.16) after two years of marriage, citing irreconcilable differences, and it has been claimed she ended their 12-year relationship over her concerns with the actor's parenting.