Champan told FOX News he received a tip that Laundrie's parents spent the night with their son in Fort De Soto Park on multiple occasions from September 1-3 and September 6-8 on Monday (September 27).
"They were registered, went through the gate. They’re on camera. They were here," he told Fox News exclusively on Monday evening. "We think at least if he’s not here right now, we are sure he was caught on camera as he went in the gate — that he was here for sure. Not over in the swamp."
However, the Pinellas County Sheriff's Office told FOX 13 in Orlando that it has received no confirmed tips or signings of Laundrie in response to Chapman's claim.
Additionally, FOX News obtained police dispatch audio of Laundrie's mother, Roberta, calling the police on Chapman, who was spotted banging on the door of the North Port, Florida home where Laundrie and Petito lived last Saturday (September 25).
“It’s a shame they wouldn’t speak with us. The police said we were welcome to knock on the door so we did. I wanted to tell the Laundries that our goal is to find Brian and bring him in alive,” Chapman told FOX News.
On Monday (September 27), authorities in Florida announced they were scaling back efforts as the FBI took over the lead in the investigation into Laundrie's whereabouts.
Last week, an arrest warrant was issued for Laundrie after a grand jury indicited him for his "use of unauthorized devices" during the events following the death of Petito, whose remains were found on September 19 in Wyoming and confirmed to be the missing 22-year-old days later.
The indictment obtained by CNN accuses Laundrie, 23, of using a debit card and PIN number for accounts that didn't belong to him between August 30 to September 1 in order to make purchases totaling more than $1,000.
A source close to Laundrie's family told CNN the 23-year-old left his own wallet and cell phone behind when he was last seen leaving his parents' Florida home 10 days ago after he initially returned to the area from a cross-country road trip without Petito, who was reported missing on September 11.
The source added that Laundrie's parents were concerned he might harm himself at the time he left their home.
An attorney for Laundrie's family emphasized that the arrest warrant isn't related specifically to Petito's death, rather incidents committed by Laundrie afterward.
"It is my understanding that the arrest warrant for Brian Laundrie is related to activities occurring after the death of Gabby Petito and not related to her actual demise," Steve Bertolino said in a statement. "The FBI is focusing on locating Brian and when that occurs the specifics of the charges covered under the indictment will be addressed in the proper forum."
"While this warrant allows law enforcement to arrest Mr. Laundrie, the FBI and our partners across the country continue to investigate the facts and circumstances of Ms. Petito's homicide," added FBI Special Agent in Charge Michael Schneider. "We urge individuals with knowledge of Mr. Laundrie's role in this matter or his current whereabouts to contact the FBI."
On September 24, local and federal authorities continue to search for Laundrie in the Carlton Reserve, a nature preserve estimated to be around 25,000 acres, in North Port near his family home after pausing September 23 due to darkness.
FOX 5 New York reported Laundrie was briefly shown in a video posted on August 19 reading the 2014 novel Annihilation by Jeff VanderMeer, which tells the story of four women venturing to Area X, with three dying and a fourth staying in the wilderness.
TikTok user @Alyssaest93 initially pointed out the video, calling it "disturbing."
"This particular book in the series follows four women. What?" wrote @alyssaest93. "So many people have said that that information needs to be handed over to the police."
Instagram user Nina Celie Angelo said she witnessed a couple involved in "a blowout of a situation" at the Merry Piglet restaurant on August 27, which she later realized could have been Petito and Laundrie after national coverage of Petito's disappearance and death, ABC 7 in New York reports.
The Blue-Collar Restaurant Group, which owns the restaurant, confirmed that it also believes Petito and Laundrie were in the Merry Piglet on the day of the alleged incident.
Angelo told ABC News Laundrie was screaming at a hostess and Petito apologized while in tears, which she witnessed from a table nearby.
"It looked as though they were like almost getting kicked out," Angelo said. "It wasn't necessarily between them, it was more so Gabby abruptly leaving the restaurant crying, and Brian was just evidently really upset, pissed off, I would say. I would say Gabby was upset, he was angry, and he was just being very temperamental towards the restaurant staff."
Angelo said she saw Laundrie walk in and out of the restaurant numerous times to confront restaurant staff.
"He was just like going in on the hostess and the waitress and then eventually the manager. He exited and entered the restaurant on four different occasions within five minutes," Angelo said. "He would walk out, walk again, walk out, walk back in. At one moment we thought he we thought they had walked out for good or he had walked out for good and he actually left for like ten minutes and then came back just to start the fight all over again."
Angelo said Laundrie apppeared to be "very visibly angry" while Petito seemed distraught during the incident, noting that she felt bad for Petito and "freaked out" by Laundrie's behavior.
"She seemed really upset. She was emotional. She was crying. She seemed kind of embarrassed," Angelo said. "At one point, she walks back into the restaurant on one of his attempts to walk back. And I think she followed him and was trying to, I think, get him to leave and, like, drop the situation. I think she was being apologetic towards the restaurant staff for his behavior. Like, she just kind of wanted to diffuse the situation. She was like, I'm sorry, come on, let's just go. But she was visibly upset."
Autopsy results have confirmed the remains found Sunday initially reported by the Federal Bureau of Investigation to be "consistent with the description of" Gabrielle 'Gabby' Petito are those of the missing 22-year-old woman and her death has been ruled as a homicide.
Teton County Coroner Dr. Brent Blue ruled Petito's death as a homicide during his preliminary findings, the FBI Denver confirmed in a post shared on its verified Twitter account.
"The cause of death remains pending final autopsy results," the FBI said, while once again listing Petito's fiancé, Brian Laundrie, as a person of interest, via CNN.
"Anyone with information concerning Mr. Laundrie's role in this matter or his current whereabouts should contact the FBI," Special Agent in Charge Michael Schneider said.
Local authorities resumed their search for Laundrie in Florida on earlier this month after his own disappearance and the FBI locating human remains that are "consistent with the description of" Petito.
"Search for Brian Laundrie will resume Tuesday in the Carlton Reserve, Venice side," the North Port Police Department announced on its verified Twitter account Tuesday morning. "We join the FBI in asking for continued public assistance by sharing any information through the tip lines."
The FBI confirmed it located human remains believed to be the missing 22-year-old woman during a news conference.
"Full forensic identification has not been completed to confirm 100% that we found Gabby, but her family has been notified of this discovery," Charles Jones, FBI Denver's supervisory senior resident agent in Wyoming, said via CNN.
The body was discovered in a national forest in Teton County, Wyoming, County Coroner Dr. Trent Blue confirmed to CNN.
Additional details were not made available as of late Sunday afternoon.
Authorities searched Bridger-Teton National Forest in Wyoming for any evidence of Petito after she was reported missing by her family days prior.
Local authorities in North Port, Florida, where Laundrie shares a home with his family, had previously confirmed "a team of more than 50" individuals continued their search for Laundrie in the Carlton Reserve, a nearly 25,000 acre wildlife refuge where his parents believe he went.
“A team of more than 50 looking for anything of note after his parents say this is where he went. We continue to corroborate all info in the search for him and Gabby,” the North Port Police Department announced on its verified Twitter account on September 19.
Authorities confirmed Laundrie was reported as missing after being named as a person of interest in the investigation earlier this month.
"The North Port Police Department and the Federal Bureau of Investigations are currently searching for 23-year-old Brian Laundrie of North Port," police said in a statement late Friday obtained by NBC News. "The family now claims that they have not seen Brian since Tuesday of this week."
Laundrie's family had requested to speak to police at the North Port, Florida home they shared with their son, who was traveling on a cross-country trip with Petito prior to her disappearance earlier this month, according to North Port spokesman Josh Taylor.
"We understand the community's frustration, we are frustrated too," North Port police said via NBC News. "For six days, the North Port Police Department and the FBI have been pleading with the family to contact investigators regarding Brian's fiancé Gabby Petito."
Petito's family, however, issued a statement saying Laundrie was not "missing," rather "hiding" amid being named as a "person of interest" in his fiancée's disappearance amid reports he'd been uncooperative during the investigation, according to the police.
“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.
Laundrie had not spoken publicly about Petito's disappearance as advised by his family attorney, Steven P. Bertolino, who claims authorities typically focus on the intimate partner in relation to similar cases.
The department confirmed it visited the Laundrie home for the first time during the investigation on Friday and relatives spoke "in detail" with investigators.
On September 16, the Moab City Police Department released body camera footage showing Petito and Laundrie each speaking with an officer about a possible domestic incident.
In the nearly hourlong video, Petito broke down in tears and claimed she was struggling with her mental health while speaking to the officer.
"I'm sorry," Petito said after the officer asked her why she was crying. "We've just been fighting this morning. Some personal issues."
Laundrie, who appeared to have scratches on his face, told police, "She had her phone and was trying to get the keys from me. I said, 'Let's just step back and breathe,' and she got me with her phone."
A responding officer wrote Petito slapped Laundrie after an argument, which led to Laundrie allegedly attempting to lock her out of the van they were traveling in. Petito then forced her way back into the van before Laundrie could drive off, according to the report.
The report states that both Petito and Laundrie told officers "they are in love and engaged to be married and desperately didn't wish to see anyone charged with a crime," NBC News reports.
Officers advised the couple to separate for the night, with Petito staying in the van, and no charges were filed in relation to the incident, according to the police report.
Petito's family said they last made communication with her in the days after the Moab incident.
Her mother, Nicole Schmidt, said the couple left Salt Lake City for Grand Teton National Park in Wyoming around August 24, which was the last time she spoke with her daughter via FaceTime.
Schmidt said she received a text from her daughter's phone until August 30, but isn't sure whether they were sent by Petito.
NBC News reports the last text sent from Petito's phone to her mother read: "No service in Yosemite."
Petito's last post on her Instagram account was shared on August 25, though a tagged location wasn't included.