People magazine reports that the American actor allegedly got "verbally abusive" and "physical" with one of his children with actress Angelina Jolie on the couple's private plane in the presence of their other kids.
The Los Angeles County Department of Children and Family Services is investigating the incident on the tarmac, People says.
TMZ.com first reported news of the investigation.
However, the LAPD told USA Today on Thursday (local time) that it was not investigating the incident, as some outlets first reported. "LAPD is not handling any report or allegations into child abuse against Brad Pitt," according to a statement read by spokeswoman Officer Jenny Houser.
USA Today also reported that the Department of Children and Family Services says by law it cannot confirm or deny investigations, according to a statement from spokesman Armand Montiel.
On Tuesday, Jolie filed for divorce from Pitt, asking for sole custody of their six children.
Cotillard denies involvelment
French actress Marion Cotillard has denied any involvement in the sudden split between the Hollywood power couple, wishing that the two will "find peace," and confirming her pregnancy with her long-time partner.
The 40-year-old posted a statement on her verified Instagram page a day after Jolie filed for divorce from Pitt, amid some media reports that Cotillard and Pitt may have been romantically involved.
Pitt and Cotillard star together in the upcoming war drama Allied.
The Oscar-winning French actress said the statement would be her only comment on the "whirlwind news that broke 24 hours ago and that I was swept up into."
"As this situation is spiraling and affecting people I love, I have to speak up. Firstly, many years ago, I met the man of my life, father of our son and of the baby we are expecting. He is my love, my best friend, the only one that I need," Cotillard said, referring to French actor Guillaume Canet.
She signed off by saying: "I do very much wish that Angelina and Brad, both whom I deeply respect, will find peace in this very tumultuous moment."
Jolie, 41 and Pitt, 52, married in 2014 after a decade together and have six children. They were steady fodder for tabloids with reports focusing on what role Jolie played in the breakup of Pitt's marriage to actress Jennifer Aniston and, more recently, possible trouble in the marriage.
- TNS and Reuters
