The FBI is searching the Florida home of Brian Laundrie, the fiancé of 22-year-old Gabby Petito, a missing woman now believed to be dead.
Agents with a search warrant surrounded the property on Monday. Mr Laundrie’s parents were removed from the home but have since been allowed back inside.
On 1 September, Mr Laundrie, 23, returned home alone a month into a cross-country road trip with Ms Petito.
On Sunday, remains matching Ms Petito’s description were found in Wyoming.
Police consider Mr Laundrie a “person of interest” in the case but have not charged him with any crime. He declined to speak to police, and went missing a few days later.
Video from local media on Monday showed officers and FBI agents approaching the Laundrie home, some with guns drawn, cordoning it off with crime scene tape and placing Mr Laundries’ parents in an unmarked van.
In a tweet, the FBI confirmed it had secured a search warrant in court but added: “No further details can be provided since this is an active and ongoing investigation.”
The agency is also set to conduct a full forensic investigation of the remains found on Sunday inside Wyoming’s Grand Teton National Park, to determine whether the woman was Ms Petito.
Body found in search for missing Gabby Petito
Since Mr Laundrie returned home, he had not spoken to authorities or to the Petito family. Mr Laundrie’s parents reported him as missing last Tuesday.
Authorities had been looking for Mr Laundrie in a 24,000-acre nature preserve in North Port, Florida, this weekend with police dogs and drones. On Monday, police called off the search, said they had “exhausted all avenues in searching” the area.
Ms Petito was visiting the Grand Teton National Park with Mr Laundrie when she disappeared.
The young couple had set out on a nomadic cross-country campervan trip in July, documenting their adventures on social media.
Two weeks before Ms Petito went missing, on 12 August, police in the southern Utah town of Moab were called to a possible domestic violence incident involving the couple.
Police released bodycam footage which showed Ms Petito crying and complaining about her mental health to officers. She also said the couple had been arguing more frequently.
The officers recommended they spend the night apart but did not file any charges. It is not yet known what happened next.