Police said Pheobe Bishop's roommate moved her body twice after murdering her, and an investigation revealed the missing 17-year-old man was in a national park.

Police said roommates allegedly murdered the missing teenager and then moved the body from the national park.

James Wood, 34, and Tanika Bromley, 33, were arrested Thursday night in the Bondberg area in southern Queensland.

They appeared in court after being charged with murder at 17.

The arrest was three weeks to three weeks after Pheobe missed the flight and disappeared.

Wood and Bromley are also charged with two counts of interfering with the body.

Police said Fiobi's body has not been found.

Police accused Wood and Bromley of driving to the airport lane in Bundaberg in a grey Hyundai IX35, but no one left the car.

Pheobe was allegedly murdered and her body moved more than once from Goodnight Bush National Park, an hour's drive from Bundaberg Airport.

Police have extensive searches of the park while investigating Pheobe's disappearance, saying the evidence may have been moved from the national park before police arrived.

The project was seized while searching for forensic information.

Detective Inspector Craig Mansfield told reporters Friday that Fiobi's body has not been found, but police suspected they were in the national park.

"We went back to a specific area and we suspected we might find pheobe, but again, it was a vast, unwelcome large area."

Telephone data led police to focus on national parks, and the search operation resumed Friday after a efforts scaled Wednesday.

"We hope we have solutions in the next few days," Mansfield said.

Police also believe they understand the motives of the Fiobi murder.

"We do have motivations for advice," Mansfield said.

Wood's SUV was seized by police on Thursday night for a forensic examination.

He has been living in the car after the gin gin property shared with Bromley, and Pheobe was declared a crime scene after the teenager disappeared.

"We think there's a car being shipped, but at this point, I won't reveal that," Mansfield said.

Mansfield said he shared the disaster that Fiobi's mother, Kylie Johnson, is experiencing.

"While we always hope to find a living pheobe, our investigation clearly shows that this is not a viable result," he said.

Wood had been detained on Wednesday but was released a few hours later.

Wood and Bromley were earlier charged with unrelated weapons crimes.

Police allegedly found shortened guns, ammunition and two copy pistols while searching Bromley’s Gray Hyundai IX35 and further ammunition in the couple’s gin gin.

Mansfield said he could not speculate until he found out whether Pheobe's body was murdered or not.

Johnson said Thursday night that her family was "breaking".

Since his daughter's "suspicious" disappearance, Johnson has posted on social media almost every day, pleading for information.

"Our world has just been broken and the scariest place I have ever been to," she wrote on Thursday night.

“I need my baby to come home and let her rest! I absolutely beg anyone who knows anything to stand up.

"We need to give her a rest, we need to give her peace."

Wood and Bromley will appear in Bondberg District Court on Friday.