Three bodies have reportedly been found in an area of northern Mexico where two Australian brothers and a friend are missing.
Reuters cited two sources with knowledge of the investigation as saying Mexican authorities had found three bodies on the Baja Peninsula, on the country's Pacific Coast.
The bodies have not yet been identified.
Local news site Zeta reported two of the bodies were found inside a well in the La Bocana area on Saturday, near where the men were believed to have been camping after abandoned tents were located on Friday.
Perth siblings Callum, 33, and Jake Robinson, 30, were travelling in the region on a surfing holiday when they failed to check into pre-arranged accommodation near the city of Ensenada.
Their mother Debra Robinson appealed for help to find her two sons and Carter Rhoad, 30, a friend from the United States they were travelling with, saying she had not heard from them since Saturday.
"Callum is a type one diabetic so there is also a medical concern," she wrote on Mexican social media.
Baja California state chief prosecutor Maria Elena Andrade Ramirez said police had questioned three people in relation to their disappearance but the chances of finding the men had diminished as a result of delays to the investigation.
"Unfortunately, a notice of their disappearance was only filed in the last few days, so very important hours were lost there," she told a news conference in Mexico on Friday.
Investigators have found a burnt-out white ute believed to be the vehicle the men were travelling in when they disappeared.
Ms Andrade Ramirez confirmed to ABC a mobile phone belonging to one of the men had been located with the three people assisting with investigations.
Officials from the Department of Foreign Affairs and Trade said it was obviously a distressing time for the family but the agency was in constant contact.
Foreign Affairs Minister Penny Wong reiterated that the government was doing everything it could to support the family.
"I can indicate that our embassy in Mexico, as well as the Australian Federal Police, are working in support of local authorities, that my department is providing consular support to the families concerned," she told reporters on Saturday.
The brothers' family is understood to be travelling from Perth to Mexico to be closer to the investigation, Nine Network reported.
The department has urged people to exercise a high degree of caution when travelling to Baja California "due to the threat of violent crime".
Drug cartels are known to operate in the region and the state's chief prosecutor said "all lines of investigation" remained open.
In 2015, Western Australian surfers Adam Coleman and Dean Lucas were murdered, believed to have been shot by gang members in the neighbouring Sinaloa region, before their van and bodies were burnt.
Australian Prime Minister Anthony Albanese, as well as opposition foreign affairs spokesman Simon Birmingham and WA Premier Roger Cook, have expressed their concerns for the surfers' safety and wishes for their safe return.
- AAP and Reuters
