Another body found at the site had been there longer and was unconnected to the latest disappearances, officials said.
Andrade said one line of inquiry is whether the deaths resulted from an attempt to steal the tourists’ pickup truck. The vehicle – which had been burned – was found nearby.
AFP journalists saw the authorities use a pulley system to extract the mud-covered bodies from the shaft on Friday near the town of Santo Thomas, about 45km (30 miles) southeast of Ensenada, a spot that is difficult to reach but popular with surfers.
3 bodies found after Australian, US surfers go missing in Mexico
3 bodies found after Australian, US surfers go missing in Mexico
The grisly discovery appeared to confirm the worst fears of the families and friends of holidaying Australian brothers Callum and Jake Robinson, and their American friend Jack Carter.
The Australian brothers’ mother Debra Robinson had sounded the alarm on a Facebook page for Baja California tourists several days ago, after they dropped out of contact.
“Reaching out to anyone who has seen my two sons. They have not contacted us since Saturday 27th April,” she wrote, attaching a poster from friends desperate for news of their whereabouts.
A missing poster shared on social media said Callum Robinson was 33, his brother Jake 30, and it named their friend as Jack Carter Rhoad, aged 30.
Callum Robinson’s Instagram showed various shots from the trio’s Mexico trip: enjoying beers with their feet up in a bar, lazing in a jacuzzi, eating roadside tacos, looking out at the surf.
Callum had played in the US Premier Lacrosse League, which left a message on its website saying the lacrosse world was “heartbroken by the tragic loss” of the trio.
“We offer our hearts, support and prayers to the Robinson and Rhoad Families, as well as all who loved Callum, Jake, and Jack,” it said.
Jake Robinson was a doctor in Perth, Australian media said.
Mexican authorities, who have arrested three suspects, were carrying out the investigation in collaboration with the US Federal Bureau of Investigation (FBI) and the Australian consulate.
A spokesperson for Australia’s foreign ministry said earlier that it was in regular contact with the Robinson family and that it “recognises this is a very distressing time.”
Baja California is known for its inviting beaches and its resorts are popular with US tourists, partly because of their proximity to the border.
It is also one of Mexico’s most violent states because of organised crime groups, although cartel activity does not commonly affect foreign tourists.
Rise in Mexican cartel violence fuels record migration to US
Rise in Mexican cartel violence fuels record migration to US
The latest case echoes that of two Australian surfers who were murdered and their bodies burned while travelling in the northwestern Mexican state of Sinaloa in November 2015.
In March 2023, alleged members of the Gulf Cartel kidnapped four Americans in the northeastern city of Matamoros, across the border from Brownsville, Texas. Two of them were killed.
Spiralling criminal violence in Mexico has claimed 450,000 lives and led to more than 100,000 disappearances since the end of 2006, when the federal government launched a controversial anti-drug strategy involving the use of military units.