Three bodies have been found in an area of northern Mexico where two Australian brothers and a friend went missing.
Mexican authorities confirmed the bodies were located on a cliff top in the Baja Peninsula, on the country's Pacific Coast, on Saturday.
Forensic tests will be undertaken by the local laboratory to identify if the bodies are missing Perth siblings Callum and Jake Robinson, the Baja California prosecutor's office said in a statement.
Investigators continue to search the rugged area where the bodies were found for additional evidence, the statement added.
Local news site Zeta reported 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.
Firefighters have reportedly worked for hours to free the bodies from the 15-metre-deep well.
Zeta also reported a fourth highly decomposed body was found in the well and is believed to be that of the owner of the property where the well is situated who has been missing for several weeks.
The Robinson brothers, both in their 30s, 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 a US friend 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 María Elena Andrade Ramírez said police had questioned three people in relation to their disappearance.
"Unfortunately, a notice of their disappearance was only filed in the last few days, so very important hours were lost there," she told a press 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 Ramírez 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.
Health Minister Mark Butler said the department was trying to glean as much information as possible from Mexican authorities to inform the family.
"This is deeply distressing to the Australian community, particularly the family and friends of these two young Australians" he 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 US State Department is also monitoring the investigation as one of the other missing men is American Carter Rhoad, 30.
Both US and Australian authorities have 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, earlier expressed their concerns for the surfers' safety and wishes for their safe return.
with Reuters
