Police are searching for the boyfriend of a woman who went missing while the couple were on a road trip across the US.

Officers in Florida say they are working with the FBI to find 23-year-old Brian Laundrie, regarded as a person of interest in the disappearance of his girlfriend, Gabrielle “Gabby” Petito.

Mr Laundrie is understood to have returned home to Florida in early September alone, after the pair left in July on a cross-country trek in a converted van to visit national parks in the American West.

Late last week, police in Utah released bodycam footage, captured on 12 August before Ms Petito’s disappearance, that showed her crying and an officer talking to Mr Laundrie after the pair were pulled over.

Officers decided to separate the couple, giving Ms Petito the van and putting Mr Laundrie into a hotel room for the night.

While they were travelling, much of their journey was documented on social media accounts, but the online content abruptly stopped and Ms Petito was last in contact with her family in late August.

Mr Laundrie later came back to Florida in the van, and Ms Petito was reported missing by her family 10 days later on Saturday 11 September.

Now, Mr Laundrie’s family have told officers they haven’t seen him since Tuesday.

Police said the first time they had been able to speak to the Laundrie family in detail about the case was on Friday evening, and that the meeting came at the family’s request.

A lawyer for the family called FBI investigators and said they wanted to talk about Mr Laundrie’s disappearance, police added.

North Port police said in a statement on Friday: “It is important to note that while Brian is a person of interest in Gabby’s disappearance, he is not wanted for a crime.”

It added that the investigation is now a “multiple missing person” case.

Mr Laundrie’s lawyer, Steven Bertolino, did not immediately respond to a request for comment on Friday night.

He had previously said that “intimate partners are often the first person law enforcement focuses their attention on”, and that he had advised Mr Laundrie not to speak.

Lawyer’s 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.

Earlier in the week, Ms Petito’s family pleaded for the Laundrie family to tell them where their son last saw her. Ms Petito and Mr Laundrie were childhood sweethearts who met while growing up in Long Island, New York.

His parents later moved to Florida.

In the body cam video released by Moab Police Department in Utah, Mr Laundrie said the couple got into a minor scuffle that began when he climbed into the van with dirty feet.

She told officers she slapped and scratched Mr Laundrie, saying: “I was trying to get him to stop telling me to calm down.”

He said he didn’t want to pursue a domestic violence charge against Ms Petito, who officers decided was the aggressor, and Mr Laundrie added: “It was just a squabble. Sorry it had to get so public.”

The police’s conversation with the family on Friday came shortly after North Port police chief Todd Garrison expressed frustration that Brian Laundrie was not helping.

The police chief had earlier tweeted: “Two people left on a trip and one person returned!”

Meanwhile, a sheriff in Utah said on Friday that detectives had determined there was no connection between Ms Petito’s disappearance on the trip and a still-unsolved fatal shooting of two women at a campsite near Moab – the same tourist town where police intervened in the fight between Ms Petito and Mr Laundrie.