Halle Berry and Gabriel Aubry have been asked to maturely come together for the sake of their daughter Nahla, four.
The parents - who split in 2010 after five years together - are currently embroiled in a bitter custody battle as Halle, 45, wants to move the child to France with fiancé Olivier Martinez.
However a custody evaluation report allegedly states that the pair need to be less immature in their approach to solving the matter.Read: Halle Berry's ex wants $20,000 child support for daughter
A source close to the situation told RadarOnline: "[The report] minces no words, and outlines in detail the fact that Halle and Gabriel can't get along. They had a very bitter break-up, and there are lingering issues of anger and mistrust of BOTH parents.
"The person that this is hurting is of course, Nahla. She loves both of her parents very much, and there is absolutely no question that Gabe and Halle are devoted to their little girl."
The insider added: "The report asserts that as the little girl gets older, if her parents aren't able to get along, it could have a very negative impact on her life. The independent child psychologist again emphasized that Halle and Gabe need to come together to co-parent Nahla, and get over the past, period. Nahla is a very well adjusted little girl, who has a very sweet disposition, and is very mature for her age, and both parents could learn a lot from her."