Police in Florida announced late Friday (Saturday NZ time) that they are collaborating with the FBI to find Brian Laundrie, 23, a person of interest in the disappearance of his girlfriend, Gabrielle "Gabby" Petito.

Laundrie's relatives informed detectives they hadn't seen him since Tuesday, according to North Port police. The talk on Friday evening (local time) was the first time police had spoken with the Laundries in-depth about the case, and the family had requested the meeting.

According to authorities, an attorney for the family contacted FBI investigators and stated that they wanted to discuss Laundrie's disappearance.

In July, Laundrie and Petito, both 22, embarked on a cross-country journey in a converted van to see national parks across the United States. Her relatives reported her missing on September 11th.

Laundrie returned to his parent's house in North Port, Florida, in his van on September 1, according to investigators. He was later named as a person of interest in the investigation.

“While Brian is a person of interest in Gabby's disappearance, he is not wanted for a crime,” North Port police said in a statement released Friday. The investigation has now become a “multiple missing person” issue, according to the report.

Steven Bertolino, Brian Laundrie's attorney, did not immediately respond to an Associated Press request for comment.

The Petito family's attorneys issued a statement declaring, "Brian is not missing."

“Gabby's entire family wants the world to know that Brian is not missing, but instead hiding. Gabby has gone missing, according to a statement from Richard B Stafford's law firm.

Petito's family had pleaded with the Laundrie family earlier this week to inform them where their son last saw her. Petito and Laundrie met as children on Long Island and became childhood sweethearts. His parents eventually relocated to North Port, which is located about 55 kilometers south of Sarasota.

According to a police video obtained by the Moab Police Department in Utah, an officer pulled the van over on August 12 after it was seen speeding and hitting a curb at the entrance to Arches National Park. Petito was shown on body camera sitting inside a police cruiser, visibly upset, while officers questioned Laundrie.

Laundrie claims the couple had a brief altercation in the video that started when he climbed into the van with dirty feet. He says he doesn't want to press domestic violence charges against Petito, who officers determined was the aggressor.

He informed the authorities he wouldn't press charges since he cared about her. “It was just a squabble,” says the narrator. “I'm sorry it had to become so public,” says Laundrie in the video.

After deciding not to press charges, Moab police separated the couple for the night, with Laundrie checking into a motel and Petito staying in the converted sleeping van.

On Friday, the official meeting with the family came after North Port Chief Todd Garrison publicly expressed his dissatisfaction with Brian Laundrie's lack of cooperation on Wednesday, asking Laundrie's lawyer to schedule a meeting.

The police chief had previously tweeted, "Two people left on a trip, and one person returned!"

Their journey in the Fort Transit van began in July on Long Island, New York, where they both grew up. According to their social media posts, they planned to arrive in Oregon by Halloween. Still, investigators said that Petito vanished after her last known communication with family in late August from Grand Teton National Park in Wyoming.

According to authorities, Laundrie drove the vehicle back to Florida by herself on September 1. Petito's family reported him missing to police in Suffolk County, New York, on Saturday.

Despite their instinct to protect their son, Petito's parents sent a letter to Laundrie's parents on Thursday through their attorney, requesting that they assist investigators to find Petito.

According to Bertolino, the Laundrie family is hopeful for Petito's safe return, but he has requested them not to communicate with the police.

In other news, a Utah sheriff said Friday that detectives have determined there is no link between Petito's disappearance on the trip and the still-unsolved shooting deaths of two women at a campsite near Moab, Utah – the same tourist town where Petito and Laundrie had the fight in which police intervened.

The bodies of the two women were discovered on August 18, six days after the traffic stop in which Laundrie and Petito were involved. Kylen Schulte, 24, and Crystal Turner, 38, had informed pals they were worried about a "creepy man" they had spotted close.

In a news statement, Grand County Sheriff Steven White stated categorically that the two cases were unrelated.