Brian Laundrie’s sister Cassie implored parents to ‘come clean’ on national TV after slamming family lawyer.

Cassie, Brian Laundrie’s sister told ABC’s “Good Morning America” Tuesday that she doesn’t know if her parents are involved in his disappearance, but added, “I think if they are, they should come clean.”

Cassie Laundrie says she has been cooperating with North Port Police. Brian’s parents live in North Port, Florida.

“I worry about him. I hope he’s OK. And then I’m angry and I don’t know what to think,” she said about Brian. “I would tell my brother to just come forward and get us out of this horrible mess.”

Cassie Laundrie said the last time she spoke to her brother was on Sept. 6 and shared a photo of her son standing next to Brian Laundrie while he was camping at Fort De Soto park, five days before Gabby Petito’s reported disappearance.

Cassie Laundrie’s comments came after she told protesters outside her Florida home Monday that her family has been ignoring her following the disappearance of her brother.

Brian Laundrie is wanted on a federal warrant for alleged debit card fraud and a person of interest in the homicide of Gabby Petito.

Laundrie was seen leaving his home on Sept. 14. His parents reported him missing three days later, before the federal warrant had been announced.