Mexican authorities have found three bodies in an area of Baja California where two Australian brothers and an American went missing.
The FBI said the bodies were found in the town of Santo Tomas and have not yet been identified, the BBC's US partner CBS News reported.
Jake, 30, and Callum Robinson, 33, from Perth, and American Jack Carter Rhoad, 30, were on a surfing holiday near the popular tourist town of Ensenada. They disappeared on 27 April.
On Thursday Mexican police questioned a woman and two men in connection with their disappearance.
Forensic tests will be conducted by a state laboratory to identify the bodies, the state of Baja California prosecutor's office said.
The office also noted on Friday that arrest warrants had been obtained for the crime of forced disappearance.
Earlier abandoned tents, a burnt white pickup truck and a phone linked to the missing tourists had been found.
A team including firefighters had been searching for the Robinson brothers and Mr Rhoad in a remote cliff area.
In a statement to CBS News, the FBI said it "cannot comment on specifics” but “we can assure you that we are assessing every tip".
"If credible, we will pursue those leads with rigour. We are in contact with the family of the US citizen, and we are steadfast with our international law enforcement partners in finding answers," the bureau added.
Baja California is one of Mexico’s most violent states, as local drug gangs fight turf wars. But the surfing conditions in Ensenada - 90 minutes south of the US-Mexico border - have long attracted tourists from California.
A US State Department spokesperson said: "We are aware of those reports and are closely monitoring the situation."
A spokesperson for Australia's foreign ministry said their embassy in Mexico was working closely with Mexican authorities and the Australian Federal Police.
