An arrest warrant has been issued for Brian Laundrie in Wyoming following a federal grand jury indictment, authorities announced Thursday.

The U.S. District Court of Wyoming issued the warrant Wednesday "related to Mr. Laundrie's activities following the death of Gabrielle Petito," FBI Denver said.

The indictment alleges Laundrie "knowingly and with intent to defraud" used an unauthorized debit card and "obtained things of value aggregating to $1,000 or more" between Aug. 30 and Sept. 1.

The investigation into Petito's death is ongoing, authorities said. The FBI in particular is seeking information from anyone who was at the Spread Creek Dispersed Camping Area between Aug. 27 and Aug. 30 and may have been in contact with the couple or saw their car.

"We urge individuals with knowledge of Mr. Laundrie's role in this matter or his current whereabouts to contact the FBI," FBI Special Agent in Charge Michael Schneider said in a statement Thursday.

North Port police shared video of the arduous effort to search through the Carlton Reserve for Brian Laundrie Thursday. Four swamp buggies and a drone from the Florida Highway Patrol are being used to search the area full of thick foliage and swamps.

About 75 personnel from 16 different agencies are on the ground Thursday, officials said.

“We’re covering many, many acres so we need all the manpower and all the staff we can grab,” Commander Joe Fussell said. “This is a tremendous mass of land … About 75% of this area is underwater.”

Early Thursday, Laundrie’s parents picked up the silver Mustang that officials towed earlier this week for processing and brought it back to their driveway. The car was towed away on Monday as a part of a search warrant related to the Petito case, the FBI said at the time.

North Port Police shared a short video of their morning briefing with various agencies and search teams at the start of their Thursday search for Brian Laundrie at Florida’s Carlton Reserve.

Relatives told police he claimed he was heading to the 25,000-acre preserve near North Port, Florida, when they last heard from him on Sept. 14.

Authorities have been scouring the area throughout the week.

Nina Angelo opened up to “Good Morning America” on Thursday about purportedly seeing Gabby Petito and Brian Laundrie at the Merry Piglets restaurant in Jackson Hole, Wyoming, on Aug. 27, three days after her last known sighting.

The Blue Collar Restaurant Group told ABC News it believes Petito and Laundrie were at its Merry Piglet restaurant and have notified the FBI. However, its security cameras don’t go that far back so there is no footage of the duo allegedly inside the eatery.

Angelo described Laundrie in vivid detail as "aggressive" and "angry".

She said the couple was in an angry confrontation with restaurant staff.

“He was just very visibly angry. [Petito] was really upset, she was crying and he immediately went to the hostess stand and was just going in on the hostess and waitress, then eventually the manager,” Angelo said.

“I think she was being apologetic towards the restaurant staff for his behavior. 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. She was crying,” Angelo said. “You could feel his temper. He was he was angry."

Authorities previously said the last time Petito was seen was Aug. 24.

Aug. 27, the day of the alleged restaurant sighting, was the same day Petito’s mom said she received a strange text from her daughter in which she referred to her grandfather as “Stan.” Petito’s mother said her daughter “never” referred to him as Stan.

The Moab, Utah, police department has released a report from a second witness claiming he saw Gabby Petito and Brian Laundrie engaged in a domestic dispute in Moab on Aug. 12.

The witness told police he observed a man and a woman, later identified Petito and Laundrie, arguing over a cellphone about 4:30 in the afternoon outside a grocery store in Moab, according to a statement from police.

"They were talking aggressively @ each other & something seemed off. At one point they were sort of fighting over a phone -- I think the male took the female's phone. It appeared that he didn't want her in the white van. He got into the driver's seat & she followed him. At one point she was punching him in the arm and/or face & trying to get into the van," the witness wrote in the police report.

The witness, according to the statement, said the woman eventually climbed over the driver to get into the passenger seat and that she was overheard saying, "Why do you have to be so mean"?

"I wasn't sure how serious this was -- it was hard to tell if it was sort of play fighting, but from my point of view something definitely didn't seem right. It was as if this guy was trying to leave her, and maybe take her phone? Not sure but wanted to help out," the witness wrote.

Around the same time, a 911 caller told a Grand County, Utah, Sheriff's Office dispatcher that he witnessed Laundrie allegedly "slapping" Petito and chasing her up and down a sidewalk hitting her, according to a recording released by the sheriff's office.