Paula Patton has made a bid to reduce Robin Thicke's access to their son after the little boy claimed he'd been hurt by his dad.
The Mission Impossible actress sought an emergency order to restrict Thicke's contact with six-year-old Julian to monitored daytime visits only, and also have him submit to drug testing, but a judge has denied her requests.
According to TMZ, Julian complained to school officials that Thicke had spanked him more than once, prompting the staff to report the incident to the Los Angeles County Department of Children and Family Services (DCFS), who opened an investigation.
The 41-year-old actress - who split from Thicke in 2015 after 10 years of marriage - began denying the singer access to their son before filing for the emergency order.
And according to legal documents, she told her 39-year-old former spouse: "Julian is scared of you."
The Warcraft actress explained in her declaration that, the day before Julian confided in school staff, he had told her that Thicke spanked him "really hard", and when he demonstrated and hit her on the back, it was very painful - but the youngster said he'd been struck even harder.
And a school official also submitted a declaration which stated Julian told her Thicke frequently "punches" him very hard, while a nanny claimed the Blurred Lines singer had smoked marijuana on several occasions in front of the little boy.
Patton also accused her ex-husband of showing up to Julian's kindergarten graduation last June drunk at 8.30am and was "hooting and hollering and making inappropriate jokes" in the Catholic church.
However, Thicke insisted in his own legal documents that his physical punishments to his son are "consistent with the law" and previously agreed with Patton.
He stated: "On a very rare occasion and only as a last resort, I will use light spanking, but it is consistent with the law - open hand on the butt. This is the type of discipline to which Patton and I agreed during our marriage."
He also claims the dispute has arisen after he stopped Patton from attending his father Alan Thicke's funeral last month.
He said in documents: "Patton did not have a positive relationship with my father and often made negative comments to me about my father. As such, she was not welcome at his funeral."
Julian has been interviewed twice by social workers on behalf of DCFS, who have also spoken to Patton.
They are expected to interview Thicke on Thursday afternoon in the US as part of their ongoing case.