Gabby Petito's parents want answers from Brian Laundrie's mom and dad

NEW YORK - The parents Gabby Petitio are accusing Brian Laundrie's parents of withholding information about her death and his disappearance.

He is the only person of interest in the case but has not been seen for 5 weeks.

Petito's mother, Nicole Schmidt spoke out in an interview with "60 Minutes Australia" this past weekend.

"I think silence speaks volumes. I believe they know probably, if not everything, they know most of the information," Schmidt said. "I would love to just, face to face, ask, 'Why are you doing this? Just tell me the truth.' "

Gabby's father, Joe Petito agrees.

"You'd think there'd be some conversations.  If Brian was staying in my house and Gabby returned to my house without him in his vehicle, I'd be on the phone with their parents," Petito said.

TIMELINE:   GABBY PETITO DISAPPEARANCE CASE

"Brian Landrie's hiding something and he's running," retired U.S. Marshal Lenny DuPaul said on the broadcast.

Petito said it's "cruel" if the Laundrie's are withholding information about what happened to Gabby or Brian.

Gabby Petito, who vanished after going on a cross-country trip with her fiance in a converted camper van, became the subject of a nationwide search after she didn’t return home.

Authorities later discovered the 22-year-old’s body in Wyoming — determined to have been the victim of a homicide. Teton County Coroner Dr. Brent Blue said a final autopsy revealed Petito’s cause of death was strangulation and confirmed the manner of death was a homicide but couldn’t say if Petito was manually strangled or strangled by an object. He believed Petito’s body was left in the wilderness for three or four weeks before being discovered.

Petito had last been in contact with her family in late August when she and Brian Laundrie were visiting Grand Teton National Park in Wyoming. Their social media posts documenting the trip abruptly stopped, and Laundrie returned to their Florida home in the van — alone, according to investigators.

Laundrie, who has not cooperated with the police, hasn’t been seen himself since Sept. 14, according to authorities. A federal arrest warrant has been issued for him in connection to the case.

"This was like evil," Nicole Schmidt said.  "She was taken at someone else's hand."