The voluntary "safety plan" was implemented last month (Sep16), shortly after Pitt's wife Angelina Jolie filed for divorce amid reports the actor had been abusive on a family plane ride.

It was set to expire on 20 October (16), but it has been extended, according to multiple sources.

Friends and family of the estranged couple, as well as staff members, are being interviewed by DCFS experts as part of the ongoing investigation.

Jolie and Pitt agreed to a temporary custody deal last month after the DCFS officials made their recommendations. The so-called "safety plan" is standard practice in any ongoing child welfare investigation. The former couple also volunteered to participate in individual counselling.

Meanwhile, Jolie was visited by two FBI agents at her home in Malibu, California, last week (ends21Oct16) to follow up on an incident that occurred on a private jet between Pitt and his 15-year-old son, Maddox, on 14 September.

Jolie filed for divorce from her husband five days later (19Sep16), citing irreconcilable differences and requesting physical custody of the couple's six kids.