Brian Laundrie's sister urges her missing, wanted brother to 'come forward'

• Brian Laundrie's sister is now urging her brother to "come forward" as the now-wanted man remains missing.
• "I would tell my brother to just come forward and get us out of this horrible mess," Cassie Laundrie said.
• The sister added, "I hope he's OK and then I'm angry and I don't know what to think."

Brian Laundrie's sister is urging her brother to "come forward" as the missing, now-wanted man who is the sole person of interest in the case of his fiancée Gabby Petito remains the subject of a massive FBI-led manhunt.

"I worry about him. I hope he's OK and then I'm angry and I don't know what to think," Cassie Laundrie said in a new Tuesday interview with ABC News' "Good Morning America" in reference to her 23-year-old sibling.

The sister added, "I would tell my brother to just come forward and get us out of this horrible mess" as she claimed she does not know where her brother may be.

"I'd turn him in," she said.

Brian Laundrie's parents reported him missing on September 17 - two days before Petito's body was discovered at a remote campsite in Wyoming and more than two weeks after Brian Laundrie returned home to Florida from a cross-country road trip without Petito.

Petito's death has been ruled a homicide.

It was revealed last week that Cassie Laundrie visited a campground at Florida's Fort De Soto Park on September 6 where her brother and parents had camped out in the days after authorities say Brian Laundrie returned home on September 1.

"We just went for a couple of hours and we ate dinner and we had s'mores around the campfire and left," Cassie Laundrie said in the "Good Morning America" interview, explaining that her family stayed for a few hours.

She continued, "There was nothing peculiar about it. There was no feeling of grand goodbye."

"I am frustrated in hindsight that I didn't pick up on anything. It was just a regular visit," Cassie Laundrie said.

She went on to say, "I don't know if my parents are involved" in the disappearance of her brother.

"I think if they are, they should come clean," the sister said.

Brian Laundrie has been named a person of interest in connection with Petito's disappearance and death. He was indicted on a charge of bank fraud on September 23.

The single-count indictment against Laundrie alleges that he "knowingly and with intent to defraud" used one or more "unauthorized access devices," including a Capital One debit bank card from August 30 to September 1 following the death of Petito.