Gabby Petito’s fiance Brian Laundrie may have lied to his parents about his whereabouts and could be “almost anywhere,” a search-and-rescue expert said.

Chris Boyer, the executive director of the National Association for Search and Rescue, told Business Insider that Laundrie may have told his family he was going to Carlton Reserve as a cover-up before going missing on Sept. 14.

"People that are trying not to get caught for something sometimes use people, right? So he may have told his parents that's where he's going," Boyer said. "They may be telling the authorities that in all honesty, but he lied to them."

Laundrie, 23, has been named a person of interest after Petito, 22, disappeared during a cross-country road trip they were on together. After his return, Petito’s body was found in Wyoming and her death was ruled a homicide.

Laundrie has refused to comment on Petito’s disappearance and his whereabouts were declared unknown by the FBI on Sept. 17, when his parents reported him missing.

Though the reporting date was only three days after he communicated with his parents, this could have given enough time for Laundrie to escape Florida, Boyer said.

“There’s any number of ways that he could have hitchhiked or somehow found a collaborator to give him a ride somewhere,” Boyer said.

Laundrie was last seen driving off, hitching an attached camper the same day Petito was reported missing.

It remains unclear whether Laundrie may have gone to the 26,500-acre Carlton Reserve in Sarasota County. Police in North Port, Florida, have used drones and bloodhounds without success.

On Monday, North Port police said they were no longer looking in the Carlton Reserve, having "exhausted all avenues."

But on Tuesday morning, the search went back to the reserve. Authorities have confirmed that it is very difficult to survive in the reserve because of the dangerous animals and limited access to safe drinking water.