The FBI - and not the Los Angeles Police Department - is handling allegations against Brad Pitt about an incident possibly involving child abuse, the department and federal sources told Fox News Thursday.

An LAPD spokesperson told us, "There was an incident that occurred on [a] plane and the FBI is currently handling it. We're not handling any investigation into this incident...[with] Brad Pitt." The LAPD spokesperson explained because the alleged incident occurred on an airplane, the investigation is out of their jurisdiction so they handed it off to the FBI.

Federal sources told Fox News that they were referred a case in regards to Pitt and his children. They have not officially determined whether there is any merit to the case, but are leaning towards referring the case back to Child Protective Services where a case does exist. This does not mean any law was broken, but that if there was a law or laws broken, the jurisdiction very likely would not reside with the FBI, but with local authorities.

An FBI spokesman said the bureau is "continuing to gather facts and will evaluate whether an investigation at the federal level will be pursued."

TMZ reported an investigation was launched after an anonymous caller reported an incident September 14 where Pitt allegedly got "physical" and "verbally abusive" with one of his children on the couple's private plane. They were reportedly flying from France back to the United States.

People reported that Jolie and their other five children were present at the time of the alleged incident.

A source told TMZ Pitt has been interviewed by authorities and is taking "the matter very seriously and says he did not commit any abuse of his children." The source added, "It's unfortunate that people involved are continuing to present him in the worst possible light."

A rep for Pitt did not return our request for comment.

Jolie filed for divorce from Pitt Monday, citing irreconcilable differences.

The actress is seeking physical custody of their six children, with visitation rights for Pitt.

Pitt released a statement to People magazine at the time saying, "I am very saddened by this, but what matters most now is the well-being of our kids. I kindly ask the press to give them the space they deserve during this challenging time."

An attorney for Jolie, Robert Offer, told the Associated Press Tuesday that her decision to divorce was made "for the health of the family."

Their children are: 15-year-old Maddox, 12-year-old Pax, 11-year-old Zahara, 10-year-old Shiloh, and 8-year-old twins Knox and Vivienne.

The couple has been together for 12 years; they married in August 2014.

It was the second marriage for Pitt, 52, who previously wed actress Jennifer Aniston, and the third for Jolie Pitt, 41, who was previously married to Billy Bob Thornton and Jonny Lee Miller.

The pair infamously got together on the set of their movie "Mr. and Mrs. Smith," while Pitt was married to Aniston.

Fox News’ Adam Housley and the Associated Press contributed to this report.