NORTH PORT, Fla. - The FBI confirmed to reporters in Florida Wednesday that investigators found what appear to be human remains, "along with personal items, such as a backpack and notebook belonging to Brian Laundrie," just hours after Laundrie's parents searched the Myakkahatchee Creek Environmental Park.
"These items were found in an area that, up until recently, had been underwater. Our evidence response team is on scene using all available forensic resources to process the area," said Michael McPherson, special agent in charge of the FBI's Tampa division. "It's likely the team will be on scene for several days."
He also identified Laundrie specifically as "a person of interest in the murder of Gabby Petito."
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McPherson is no stranger to the case. He was seen Sept. 20 at the Laundrie's North Port home as agents executed a search warrant.
In response to the update, Laundrie family attorney Steven Bertolino told Fox News Digital Chris and Roberta Laundrie "were at the reserve earlier today when human remains and some of Brian's possessions were located."
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Bertolino said the findings were discovered "in an area where they had initially advised law enforcement that Brian may be." He added: "Chris and Roberta will wait for the forensic identification of the human remains before making any additional comments."
The FBI's announcement came hours after Bertolino revealed that "some articles belonging to Brian were found" while the Laundries and law enforcement were searching within the park along a trail that their son was known to frequent.
The Sarasota County Medical Examiner's Office confirmed that it subsequently responded to the area at law enforcement's request. A senior law enforcement source told Fox News' David Spunt at the time that "what appear to be human remains" were found at a site being searched by a cadaver dog within the park.
As of Wednesday, the park was closed to the public, having reopened only Tuesday following a weeks-long search for the fugitive.
The Laundries, who have claimed their son went to Myakkahatchee on Sept. 13, the day he was last seen, left their North Port home just before 7:15 a.m. local time for the environmental park. At the park, two men in hiking gear - including at least one who later identified himself as a law enforcement officer - began trailing behind them. The Laundries and one of the men appeared to discuss a discovery before the parents left the park, which was subsequently closed to media and the public.
During the couple's time inside the park, Chris Laundrie could be seen continually moving in and out of areas of the brush. After a short while, he and Roberta Laundrie separated, with Chris and the two men moving into brush on the left side of the trail for approximately 12 minutes.
Chris returned without law enforcement, and the couple continued on. The Laundries later discovered a white bag and a dark-colored object after traveling through a patch of brambles at the edge of the brush at a clearing. They then could be seen putting the object into the bag and handing it over to the law enforcement officer shortly thereafter.
On their way out of the park, the couple made a phone call and then received a call.
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Exclusive video obtained by Fox News Digital shows the Laundries and the law enforcement officer huddling and speaking as the officer appears to show the couple a discovered object. The officer appeared to tell the parents: "I think we might have found something." The officer could be seen patting Chris Laundrie's shoulder as he huddled with the couple.
The couple left the park at 8:45 a.m. The Laundries returned home shortly thereafter and appeared emotional when confronted by protesters there.
Brian Laundrie has been named a person of interest in the disappearance and subsequent homicide of his fiancée, Gabby Petito. The FBI later issued a warrant for his arrest on charges related to his unauthorized use of a bank card.
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Chris and Roberta Laundrie said Brian, 23, left his family's North Port, Florida, home on Sept. 13 to hike in the Myakkahatchee Creek Environmental Park, located alongside the T. Mabry Carlton Jr. Memorial Reserve. The Laundries' attorney had initially identified the date of Brian's disappearance as being Sept. 14 before changing the timeline weeks later.
Since his disappearance, state, local, county and federal law enforcement have extensively searched the reserve and the Myakkahatchee, where Laundrie is said to have parked his car at the time.
His family did not announce until Sept. 17 - four days after he allegedly left - that he had not returned.
Laundrie and 22-year-old Petito left for a trip in mid-June with the plan to visit national parks in her white converted Ford Transit. The couple had met years earlier on Long Island, New York, where they grew up and later moved into the North Port home with Brian's parents.
Brian Laundrie arrived back in North Port on Sept. 1 - with the van, but without Petito.
Petito's mother, Nichole Schmidt, reported her missing to Suffolk County Police in New York on Sept. 11. Search teams discovered Petito's body near Wyoming's Grand Teton National Park on Sept. 19 and announced shortly thereafter that she had been the victim of a homicide.
Authorities later said she died of "manual strangulation."
Fox News' David Spunt contributed to this report.