A friend of Brad Pitt has said reports that the Hollywood star struck his son during an altercation are "exaggerated and fabricated." The actor has been the focus of intense speculation after his wife of two years Angelina Jolie, filed for divorce on Monday (19 September) citing the "health of her family" as the reason for the split.

It was later alleged that the Hollywood couple's relationship came to a head following a drunken row aboard a plane, during which it was claimed their eldest son Maddox, 15, was struck, after he attempted to intervene between his quarrelling parents.

A source close to the actor has slammed the allegations that the World War Z star struck the teenager either 'intentionally or inadvertently'. "These claims are exaggerated and fabricated," the source told DailyMail.com. "'It's unfortunate for the whole family that people are insisting on continuing this endless smear campaign against Brad that hurts everyone.

"They are a solid family with two caring parents and a normal share of verbal disagreements like major households. Hopefully people can move on and leave them all alone to work this out," the source added.

It has also been reported that the alleged incident may have been caught on CCTV footage on board the plane. According to US Weekly, cameras at Minnesota's International Falls Airport captured the argument between Maddox and Pitt. A source who saw the video claims: "Brad is seen yelling a lot during it, but nothing physical."

Following the sensational news that the couple are to split, it was reported that the alleged incident would be investigated by the FBI, the LA County Department of Children and Family Services. On Thursday morning, a police car was seen arriving at the Jolie-Pitt compound in the Hollywood Hills, where Pitt is believed to be staying. Jolie and the children have moved into a rental home in Malibu.

A statement from the FBI said: "In response to your inquiry regarding allegations within the special aircraft jurisdiction of the United States; specifically, an aircraft carrying Mr. Brad Pitt and his children, the FBI is continuing to gather facts and will evaluate whether an investigation at the federal level will be pursued."

Meanwhile, Pitt's friend added that, despite the smear campaign against him, the actor refuses to be drawn into a public battle with Jolie and continues to have a huge amount of respect for the mother of his children. "He is focused on the best interests of the kids right now, that is why he has remained silent despite the smears," his friend explained.

The 52-year-old was said to be blind-sided by his wife's divorce petition and had urged her to conduct the split in private for the sake of the children. "He was appealing to her to do this quietly – not to save the marriage but to consider the well-being of the children – and it was ignored," a source close to the actor told People.

Angelina Jolie and Brad Pitt
A source close to Pitt claims the alleged altercation between the father and his teenage son Maddox was 'exaggerated and fabricated' Robyn Beck/Getty

While Pitt's ex-wife Jennifer Aniston has reportedly told friends that she wasn't surprised by the couple's marital breakdown, sources close to the couple have revealed that the relationship was tumultuous and they both reached 'breaking point.'

"There was clearly a breaking point, where she'd just had enough. He may have been broken himself and said he couldn't go on, and she reacted. This has been difficult for a while."

A source close to Jolie added: "'Things built and built over time – it wasn't any one thing. She's loved this man for several years, and [divorce] is not something you do impulsively. They have six kids together and are always going to be in each other's lives." The source added that Jolie did "what she needed to do."

The Maleficent actress has applied for physical custody of the children with visitation rights for their father. TMZ reports that Pitt will be seeking joint custody of the couple's three biological children as well as their three adopted children Maddox, 15, Pax, 12, and Zahara, 11.