The FBI is gathering information about an alleged altercation involving Brad Pitt on an aircraft carrying the actor and his children.
Brad's wife Angelina Jolie filed for divorce on Monday, citing irreconcilable differences, and has asked for physical custody of the couple's six children.
Several media outlets, using anonymous sources, have reported that the Ocean's Eleven star is under investigation by a child welfare agency after allegedly clashing with one of his children.
In a statement, the FBI said allegations involving an "aircraft carrying Mr Brad Pitt and his children" had been referred to the agency.
"The FBI is continuing to gather facts and will evaluate whether an investigation at the federal level will be pursued," it added.
The reported incident is an alleged altercation between Brad and a family member, a source said.
Los Angeles County Department of Children and Family Services said it could not confirm or deny whether it was investigating Brad.
Meanwhile, a Los Angeles Police Department (LAPD) spokeswoman said: "The LAPD is not handling any reports or allegations into child abuse against Mr Brad Pitt."
A spokesman for the force later said that a report of an incident on a plane involving Brad been passed to the FBI, but refused to confirm any details about the allegations.
Brad was on a plane that landed at the International Falls, Minnesota, airport on September 14, local sheriff Perryn Hedlund said.
Angelina, 41, and Brad, 52, known collectively as Brangelina, married in 2014 after 10 years together.
Angelina's lawyer Robert Offer said the actress had filed for the dissolution of the marriage "for the health of the family".
In legal documents filed with the Los Angeles Superior Court, the Maleficent star asked for physical custody of the couple's children - Maddox, 15, Pax, 12, Zahara, 11, Shiloh, 10 and eight-year-old twins Knox and Vivienne. She also filed for Brad to be granted child visitation rights and to share legal custody of the children.
Angelina is being represented by divorce lawyer Laura Wasser, who helped in her divorce from Billy Bob Thornton and has represented Johnny Depp in his divorce from Amber Heard.
In a statement following news of the divorce, Brad said he was "very saddened" and "what matters most now is the well-being of our kids".
The couple first met when they played married spies in the film Mr And Mrs Smith, when Brad was still married to Friends star Jennifer Aniston.
Angelina was previously married to Thornton and British actor Jonny Lee Miller.