The parents of two Australian brothers shot dead in one of Mexico’s most dangerous states say “the world has become a darker place for us” after identifying their sons’ remains.

Callum, 33, and Jake Robinson, 30, were on a surfing trip with American friend Carter Rhoad, 30, in northern Mexico when they failed to check in to pre-arranged accommodation near the city of Ensenada.

When police arrived at their last known whereabouts, they discovered a campsite covered in blood.

Days later, three bodies were found in a well and on Sunday, their families confirmed their identities.

On Tuesday, Debra and Martin Robinson said they had been “overwhelmed” by the “outpouring of emotion and support” for their sons, adding: “We know they were truly loved and impacted many people’s lives”.

“Our hearts are broken and the world has become a darker place for us,” Debra said from San Diego.

“Now it’s time to bring them home to family and friends and the ocean waves in Australia.

“Please, live bigger, shine brighter and love harder in their memory.”

The couple remembered Callum as a “loveable, larger-than-life character” and Jake as a “happy, gentle and compassionate soul”.

“We have always been very proud of their academic and sporting achievements and admired their life choices.”

Martin took the opportunity to thank friends and family in Australia and the US for being a “massive support” as well as numerous Australian government agencies including DFAT, AFP and the Australian embassy in Mexico.

Baja California state prosecutors believe the alleged killers were driving by when they spotted the foreigners’ pick-up truck. They attempted to steal its tyres and parts but the men resisted.

All three were found with bullet wounds to the head.

The alleged murderers attempted to destroy the evidence, burning the tent and driving the coveted pick-up away before setting it alight as well.

The bodies were dumped in a 4m-deep well about 6km away, on top of a fourth body prosecutors say had been there much longer.

Three suspects are being held in connection with the case – two of them because they were caught with methamphetamine but continue to be suspects in the killings.

A criminal charge of forced disappearance, equivalent to kidnapping, was laid against one of the three on Saturday, but that was before the bodies were found. It was unclear if he might face more charges.

In keeping with Mexican law, prosecutors identified him by his first name, Jesús Gerardo, alias “el Kekas”. He has a criminal record of drug dealing, vehicle theft and domestic violence.

7NEWS understands authorities have not ruled out the possibility that others were involved in the killings.

On Monday, authorities returned to the site where the Robinson brothers had set up camp in the hours before their deaths to look for evidence.

Baja California is well known for beautiful beaches and tiny villages but the northern border states are also rife with violent crime, with the Australian government’s Smartraveller website warning of drug-related crime and gang violence.

Mexico’s Foreign Minister Alicia Barcena has offered condolences to the men’s family as surfers in San Miguel held a paddle-out in tribute to the trio. More than 100 people also gathered for a vigil in San Diego, where Callum lived.

However, locals have noted the deaths of the three tourists were solved far quicker than the disappearances of thousands of Mexicans, many of whom were likely victims of the nation’s drug wars.

– with AP and AAP