Police in Florida said late Friday (US time) that they are working with the FBI to locate 23-year-old Brian Laundrie, a person of interest in the disappearance of his girlfriend, Gabrielle "Gabby" Petito.
Attorneys for the Petito family released a statement saying "Brian is not missing".
"All of Gabby's family want the world to know that Brian is not missing, he is hiding. Gabby is missing," the statement from the law office of Richard B Stafford said.
North Port police said in a statement that Laundrie's family told officers they haven't seen him since Tuesday. Police said the conversation Friday evening was the first time they'd spoken with the Laundries in detail about the case, and that the meeting came at the family's request. An attorney for the family called FBI investigators and said they wanted to talk about Laundrie's disappearance, police said.
Laundrie and Petito, 22, left in July on a cross-country trek in a converted van to visit national parks in the US West. She was reported missing on September 11 by her family.
Investigators said Laundrie returned in the van to his parents' home in North Port, Florida, on September 1. He was then identified as a person of interest in the case.
"It is important to note that while Brian is a person of interest in Gabby's disappearance, he is not wanted for a crime," North Port police said in Friday's statement. It added that the investigation is now a "multiple missing person" case.
An attorney for Brian Laundrie, Steven Bertolino, did not immediately respond to a request for comment from the Associated Press on Friday night.
Earlier in the week, Petito's family pleaded for the Laundrie family to tell them where their son last saw her. Petito and Laundrie were childhood sweethearts who met while growing up on Long Island. His parents later moved to North Port, about 55km south of Sarasota.
Police video released by the Moab Police Department in Utah showed that an officer pulled the van over on August 12 after it was seen speeding and hitting a kerb near the entrance to Arches National Park. The bodycam video showed an emotional Petito, who sat inside a police cruiser while officers also questioned Laundrie.
Laundrie says on the video the couple got into a minor scuffle that began when he climbed into the van with dirty feet, and said he didn't want to pursue a domestic violence charge against Petito, who officers decided was the aggressor.
He told the officers he wasn't going to pursue charges because he loves her. "It was just a squabble. Sorry it had to get so public," Laundrie says on the video.
Ultimately Moab police decided not file any charges and instead separated the couple for the night, with Laundrie checking into a motel and Petito remaining with the converted sleeper van.
The official conversation with the family Friday came shortly after North Port Chief Todd Garrison had publicly vented frustration over Brian Laundrie's lack of help on Wednesday, pleading for Laundrie's lawyer to arrange a conversation.
"Two people left on a trip and one person returned!" an earlier tweet by the police chief had said.
Their trek in the Fort Transit van began in July from New York's Long Island, where both grew up. They intended to reach Oregon by Halloween according to their social media accounts, but Petito vanished after her last known contact with family in late August from Grand Teton National Park in Wyoming, authorities said.
Laundrie drove the van back to Florida on September 1 alone, police said. Petito's family filed a missing persons report last Saturday with police in Suffolk County, New York.
Petito's parents had released a letter through their attorney on Thursday to Laundrie's parents, asking them to help investigators locate Petito, despite their instinct to protect their son.
Bertolino, Laundrie's attorney, said the Laundrie family are hoping for Petito's safe return, but he had asked them not to speak with investigators.
In other developments, a sheriff in Utah said Friday that detectives have determined there is no connection between Petito's disappearance on the trip and a still-unsolved slaying of two women who were fatally shot at a campsite near Moab, Utah — the same tourist town where Petito and Laundrie had the fight in which police intervened.
The two women's bodies were found August 18, six days after the traffic stop involving Laundrie and Petito. The two women, Kylen Schulte, 24, and Crystal Turner, 38, had told friends they feared a "creepy man" they had seen nearby might harm them.
Utah's Grand County Sheriff Steven White said without elaboration in a news release the two cases were unrelated.