Paula Patton's appeal to limit former husband Robin Thicke's joint custody of their son, Julian (6), has been denied by a judge on Thursday (12 January).

The 41-year-old actress appeared in a Los Angeles court and alleged Thicke of "excessive spanking" their son. She also asked for the singer to only have monitored daytime visits.

"Over the past year, I have become concerned about [Robin]'s drinking and drug use, as well as the forms of punishment he is using to discipline Julian," Paula wrote in her declaration, according to Entertainment Tonight.

"My concerns culminated on January 4, 2017, when Julian's school called Department of Child Family Services (DCFS) to report what they believed to be credible allegations of abuse from Julian against [Robin]."

"We asked him to show us how hard, and I asked him to hit me on my back," Patton said, adding "Julian said it was worse than that."

Thicke in his declaration claimed that his former wife denied him access to his son following the "excessive spanking" incident.

"It is my understanding that Paula is accusing me of 'excessive spanking.' I am told that Julian reported to the school that I spanked him and that the school made a report to the Department of Children and Family Services," Thicke said.

"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 Paula and I agreed during our marriage."

Thicke in the court papers also said that Patton has a grudge against him as he did not permit her and her family to attend the funeral of his father Alan, who passed away on 13 December at the age of 69.

"It is my belief that Paula holds residual anger toward me because I and my family would not permit her or her family to attend the funeral of my father on December 20, 2016," Robin said in his declaration.

Thicke also said that he is cooperating with the DCFS investigation and is meeting with a social worker on Thursday with his son.

"I understand that the social worker has already met with Julian, Paula, and employees from Julian's school, and that DCFS has not sought to remove Julian from my care, placed any restrictions on my custody, nor instructed Paula to withhold Julian from me. I have certainly not heard from anyone in this regard at any time," he said.

Paula and Robin split in February 2014 after nine years of marriage. Their divorce was finalized in March 2015.