As the FBI continues its investigation into allegations that Brad Pitt verbally and physically abused his teenaged son, reports say the Hollywood star is “devastated” by his split with Angelina Jolie.

The ‘Brangelina’ break-up became messy quickly after claims emerged that Pitt abused 15-year-old Maddox on a private jet on September 14.

Because the incident occurred in mid-air, the matter comes under the jurisdiction of the FBI, which is reportedly continuing to gather information before determining whether to open an investigation.

FBI spokeswoman Laura Eimiller told the Associated Press the agency hasn’t made a decision on a formal investigation into what occurred on the plane, which was carrying Pitt, Jolie and their six children.

The FBI is still considering whether to open a formal investigation into Pitt. Photo: Getty

The Los Angeles County Department of Children and Family Services is also continuing to look into the incident, according to People Magazine.

US Weekly quoted a friend of Pitt as saying the actor “is beside himself and has been crying” after the much-publicised split.

“He was completely caught off guard and blindsided and had no idea she would do this,” the source was quoted as saying.

Jolie filed for divorce on September 19 citing irreconcilable differences, ending one of Hollywood’s most glamorous and powerful couples. The pair had been together for more than 10 years and married for two.

“Angelina filed the court papers a minute before the courts closed on Monday night,” US Weekly quoted the Pitt source. “He didn’t have a lawyer or anything. She had threatened divorce in the past but he did not think she would file this time.”

At the time the divorce petition was filed, Jolie’s lawyer Robert Offer released a statement saying the “decision was made for the health of the family”.

Jolie is not seeking spousal support, but wants sole physical custody of their six children and for Pitt to have visitation rights.

However, she is happy to share legal custody with Pitt, meaning they would both be responsible for all decisions pertaining to their children.

Pitt has reportedly had no access to the children since Jolie filed for divorce, when they and the actress moved into a rented Malibu home.

Brad Pitt, Angelina Jolie and son Maddox in happier times.

“He [Pitt) is beside himself and has been crying,” the source told US Weekly. “He was completely caught off guard. Brad is in a mess right now. He isn’t able to see the kids and he is desperately trying to make sure they are OK by calling valued members of his and Angelina’s staff.

“He isn’t worried about his own reputation right now. His complete and utter devastation has come from what his children are going through,” the report added.

Pitt and Joie share six children between them including Maddox, 15, Pax, 12, Zahara, 11, Shiloh, nine, and eight-year-old twins Vivienne and Knox.

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