Robin Thicke's and Paula Patton's custody battle is getting even uglier ...

Police were called to Patton's Calabasas home on Friday, but the Lost Hills Police Department in Malibu isn't giving many details: "All I can say is that basically we had a call to respond for a civil matter. No action was taken on our part, no report was written. It was completely civil," a police spokesperson said.

Apparently, Patton violated the custody order that allows for temporary joint custody with ex Robin Thicke. In a video posted on TMZ, Patton appears to be thanking police officers. The site reports Patton violated their custody order by refusing to release the couple's 6-year-old Julian to his dad. The report says Julian stayed inside the home and refused to go with his father because he was "scared."

Thicke is currently under investigation by the Los Angeles Department of Child and Family Services for Patton's allegations that Thicke spanks their son. Julian's school even filed a report with DCFS Jan. 3, resulting in the department interviewing Thicke on Jan. 12. In court documents, Thicke states: "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."

Paula says their son Julian's behavior has become cause for concern since he has become aware that Robin knows Julian has complained about the spanking.

Meanwhile, Robin thinks all of Paula's complaints stem from her anger at not being invited to her late former father-in-law Alan's funeral last month. Court papers state, "It is my belief that Paula holds residual anger towards me because I and my family would not permit her or her family to attend the funeral of my father on December 20, 2016. Paula did not have a positive relationship with my father … As such, she was not welcome at his funeral. It is my belief that Paula only wanted to attend because it would have resulted in additional public exposure for her."