The New York Post reported that the co-worker described Laundrie as "well versed" in spending long periods in the woods surviving on "nearly nothing."
Authorities are searching for Laundrie, who is a person of interest in the death of his fiancée and fellow Long Island native Gabby Petito, in a large wildlife preserve in Florida.
His parents reported on Friday, Sept. 17, that they had not seen Laundrie since Tuesday, Sept. 14.
Petito, a 2017 graduate of Bayport-Blue Point High School in Suffolk County, had been traveling across the country with Laundrie in her van.
Laundrie returned to his parents' home in Sarasota County, Florida on Wednesday, Sept. 1 without Petito, and later refused to cooperate with authorities as they began searching for the 22-year-old.
Her remains were found on Sunday, Sept. 19, in a Wyoming national park.
On Thursday, Sept. 23, a federal arrest warrant was issued for Laundrie.
The warrant is not for Petito's homicide itself, but "is related to activities occurring after the death of Gabby Petito and not related to her actual demise," the FBI said.
"The FBI and our partners remain dedicated to ensuring anyone responsible for or complicit in Ms. Petito's death is held accountable for their actions," FBI Denver Special Agent in Charge Michael Schneider said in a statement on Tuesday, Sept. 21. "Mr. Brian Laundrie has been named a person of interest. Anyone with information concerning Mr. Laundrie's role in this matter or his current whereabouts should contact the FBI."
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