NORTH PORT, Fla. (NewsNation Now) — Authorities say a body discovered Sunday in Wyoming is believed to be Gabrielle “Gabby” Petito.

The FBI said the body was found by law enforcement agents who had spent the past two days searching campgrounds on the east boundary of the park.

Petito and her boyfriend, Brian Laundrie, left in July on a cross-country trek in a converted van to visit national parks in the U.S. West.

Police said Laundrie was alone when he drove the van back to his parents’ home in North Port, Florida, on Sept. 1. Petito’s family filed a missing person report on Sept. 11 with police in Suffolk County, New York.

Police searched a vast Florida wildlife reserve on Sunday for Laundrie, a person of interest in the case. The 23-year-old was last seen Tuesday by family members in Florida, and investigators have been searching for him for the past two days in a 24,000-acre wildlife reserve near Sarasota, Florida.

Police say Laundrie’s missing status is “certainly a twist.”

“We’re hopeful that he’s out here,” says Josh Taylor, a North Point Police spokesperson. “Certainly, we’ve prepared for all different possibilities, but our goal is to locate him and bring him back to North Port.”

Authorities used drones, scent-sniffing dogs and all-terrain vehicles in the reserve, which has more than 100 miles of trails, as well as campgrounds. Investigators took some of his clothing from his parents’ home Friday night to provide a scent for the search dogs.

“His family says they believe he entered the area earlier this week,” North Port Police tweeted Saturday.

Investigators in Florida were hopeful Laundrie was somewhere in the wildlife reserve near Sarasota. Depending on his skills, he could survive out in the reserve for some time, said police spokesperson Josh Taylor at a news conference.

“Certainly, we prepare for all different possibilities, but you know, our goal is to locate him and bring him back to North Port,” Taylor said.

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.

Investigators were trying to verify the story told by Laundrie’s family members that he went in the reserve with only a backpack, Taylor said. One mystery is how Laundrie got to the reserve. Family members told investigators he took his car, but the vehicle was found back at his family’s home, not at the reserve.

Earlier, the North Port Police said in a statement that they understood the community’s frustration over the lack of progress in finding the missing woman.

“We are frustrated too,” the statement said. “For six days, the North Port Police Department and the FBI have been pleading with the family to contact investigators regarding Brian’s fiance, Gabby Petito. Friday is the first time they have spoken to investigators in detail.”

“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.

Attorneys for the Petito family released a statement saying Laundrie was 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, 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, New York. His parents later moved to North Port, about 35 miles south of Sarasota.

The couple’s trek in the Ford Transit van began in July from Long Island. They intended to reach Oregon by the end of October, 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.

Police video released by the Moab Police Department in Utah showed that an officer pulled the van over on Aug. 12 after it was seen speeding and hitting a curb 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.

Ultimately, Moab police decided not to file any charges and instead separated the couple for the night. Laundrie checked into a motel and Petito remained with the converted sleeper van.

The Associated Press and NewsNation affiliate contributed to this report.