The family of Brian Laundrie, the boyfriend of 22-year-old Gabby Petito, who went missing while the couple was on a cross-country trip, said Friday night his whereabouts are now unknown, too.

       "Be advised that the whereabouts of Brian Laundrie are currently unknown," an attorney for the family said. "The FBI is currently at the Laundrie residence removing property to assist in locating Brian. As of now the FBI is now looking for both Gabby and Brian."

       The development was the latest in a case that has grabbed national attention as the couple had been traveling across the country since June in her 2012 Ford Transit van and documenting the trip on social media. Laundrie returned home to North Port, Florida, on Sept. 1 without his girlfriend, according to police.

       Petito's parents reported her missing on Sept. 11 after not speaking with her for two weeks.

       The Moab Police Department via AP

       This police camera video provided by The Moab Police Department shows Brian Laundrie talking to a police officer after police pulled over the van he was traveling in with his girlfriend, Gabrielle Petito, near the entrance to Arches National Park on Aug. 12, 2021. The couple was pulled over while they were having an emotional fight.

       Petito was last seen on Aug. 24 leaving a hotel room in Utah. The next day, she spoke to her mother, Nichole Schmidt, telling her that their next stops would be at Grand Teton and Yellowstone, Schmidt told ABC News this week.

       Schmidt received two text messages from her daughter's phone in the days after speaking to her, but it was unclear whether they were actually sent by Petito.

       Laundrie has been named a person of interest in the case, but he has so far refused to speak to police.

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       "Many people are wondering why Mr. Laundrie would not make a statement or speak with law enforcement in the face of Ms. Petito's absence," the attorney representing the Laundrie family, Steven P. Bertolino, said in a statement Wednesday. "In my experience, intimate partners are often the first person law enforcement focuses their attention on in cases like this, and the warning that 'any statement will be used against you' is true, regardless of whether my client had anything to do with Ms. Petito's disappearance. As such, on the advice of counsel, Mr. Laundrie is not speaking on this matter."

       The North Port Police Department said Friday afternoon it had entered the family's home, where Brian was believed to be staying, to speak with the family "at their request."

       Courtesy Nichole Schmidt and Joseph Petito

       Gabby Petito, 22, disappeared during a cross-country trip with her boyfriend over the summer.

       The police later tweeted, "The conversation at the Laundrie home is complete. Once we have the details, a statement will be made. We ask for calm! Please let us work through this and information will be forthcoming."

       It was after that tweet that the family lawyer released the statement saying the location of Brian Laundrie was unknown.

       People had gathered outside the Laundrie home throughout the day Friday, some with bullhorns, chanting "Where is Gabby?" and calling on Brian Laundrie or the family to talk to authorities. Those people were moved from the lawn to the sidewalk as they chanted toward the house.

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       Brian's sister, Cassandra Laundrie, spoke to ABC News on Thursday night, saying she had spoken to police about Petito's disappearance but was mostly learning details from the news.

       "Obviously, me and my family want Gabbie to be found safe," she said. "She is like a sister and my children love her, and all I want is for her to come home safe and sound and this be just a big misunderstanding."

       Earlier in the day, the Grand County Sheriff's Office in Moab, Utah, said Petito and Laundrie did not appear to be connected to the murders of two women at a campground in mid-August. The sheriff's office said on Thursday it had been in contact with Florida authorities about investigating a possible connection to the double murder.

       Courtesy Nichole Schmidt and Joseph Petito

       Gabby Petito is pictured with her boyfriend, Brian Laundrie, in a photo posted to Petito's Instagram account on March 17, 2020.

       The two women were last seen leaving a bar on Aug. 13, one day after authorities were called about a disagreement between Petito and Laundrie while they were traveling in Moab.

       The couple's white van had been pulled over after a witness called police about an altercation between the two at the Arches National Park. The couple admitted to arguing and that Petito had slapped Laundrie, according to the report. Both told police that Laundrie had not Petito.

       There was "insufficient evidence existed to justify criminal charges," Moab Police Department Chief Bret Edge said in a statement Tuesday

       ABC News' Alondra Valle, Julia Jacobo and Matt Foster contributed to this report.