Kate Gosselin appears to have her brood of eight under control on TLC’s "Kate Plus 8," but behind closed doors, one report is suggesting that may not be the case. After years of combating child abuse claims, Gosselin is once again being accused of mistreating at least one of her children.

According to a report in InTouch magazine via Radar Online, Gosselin, 39, was recently investigated by child services regarding the treatment of one of her 10-year-old sextuplets, Collin. The investigation is said to have occurred after an unknown individual contacted Pennsylvania's Berks County Children and Youth Services accusing her of being “both physically and psychologically abusive” to her son.

An insider expanded on the claims alleging that Gosselin “always picks on Collin” and treats him differently from her seven other children. “[She] disciplines him more severely than his siblings. He often eats meals alone,” an insider told InTouch.

Gosselin's 14-year-old twins Mady and Cara and the other sextuplets, Aaden, Leah, Alexis, Hannah and Joel, also have reportedly noticed their mother's alleged misbehavior. “[They] see how Kate treats their brother like he’s an indentured servant,” said the insider.

The children's father and Kate’s ex-husband, Jon Gosselin, 37, is said to be attempting to gain full custody of the children in response to the abuse claims. “He can’t stand by and let this go on. Enough is enough,” said a source.

In 2012, Jon’s former friend and “Kate Gosselin: How She Fooled the World” author Robert Hoffman admitted to calling Child Protective Services (CPS) on Kate twice in 2010. He told Radar Online he made the calls after gaining access to Kate’s journal entries and various documents -- from her reportedly tossed computer hard drive -- which allegedly contained questionable entries regarding the treatment of her children.

“I sent them copies of what I had and they told me they would look into it and that’s the last I heard,” Hoffman said of his contact with CPS. “I tried to talk to Kate several times in 2010 but she wouldn’t acknowledge my existence."