A Mexican court on Wednesday ordered the alleged murderer of two Australians and an American killed during a surfing trip to be prosecuted, as chilling details emerged about the suspect's alleged confession.

It followed a hearing held for Jesus Gerardo "N" — alias "El Kekas," a slang word that means quesadillas — in Ensenada, Baja California, where the bodies of brothers Callum and Jake Robinson, and their friend Jack Carter Rhoad, were found last Friday.

The suspect's girlfriend told a court that he confessed to killing the three friends after returning home from their campsite, the BBC reported. The 23-year-old woman told investigators he showed up at her house on April 28, telling her he had done something to "three gringos," the outlet reported.

She said she asked what he meant, and he replied "I killed them", the court was told.

He then showed her new tires that were allegedly stolen from the three surfers, the BBC reported, citing prosecutors.

The suspect will be prosecuted for the crime of "disappearance committed by private individuals," and homicide charges are expected to be filed later, the state prosecutor's office said.

The trio had been camping in a remote beachside area when they were killed in what investigators believe was an attempt to steal their pickup truck.

Their bodies were found in a cliff-top shaft with bullet wounds to the head.

The prosecution has said it is gathering evidence to charge two other suspects, who remain in detention for alleged possession of methamphetamine.

Baja California, located just south of California, is popular with US tourists thanks to its inviting beaches.

It is also one of Mexico's most violent states because of organized crime gangs, although tourists are not usually targeted.

On Tuesday, the forensic service delivered the victims' bodies to a funeral home in Baja California that will transfer them to the United States, where the families are waiting for them.

The parents of the two Australian brothers urged well-wishers to use their memory as an inspiration to "live bigger, shine brighter and love harder."

Speaking from California, Debra and Martin Robinson said that "the world has become a darker place" since the deaths.

Martin thanked friends and family in Australia and the United States who have offered "overwhelming support" since the men went missing.

With the ocean at their backs, mother Debra then struggled to read through prepared remarks.

"It is with heavy hearts that we share the news that Callum and Jake have been murdered," she began, her voice cracking with emotion. "Our hearts are broken and the world has become a darker place for us."

She described Callum, aged 33, as a "lovable, larger-than-life character" who played professional lacrosse in the United States, where he became known as "the big koala."

The U.S. Premier Lacrosse League left a message on its website saying the lacrosse world was "heartbroken by the tragic loss" of the trio.

Callum also played lacrosse at Stevenson University in Maryland. Head lacrosse coach Paul Cantabene told CBS Baltimore he was devastated when he learned the news.

"I had a good cry, and then I had to make some tough phone calls and notify some people about the situation," Cantabene said. "That was even tougher." 

On social media, his devastated girlfriend shared a black and white photo of the couple kissing, with the message: "You are one of one. I will love you forever." In another photo she shared, in which the two can be seen embracing,  she wrote: "My heart is shattered into a million pieces. I don't have the words right now."

Jake, aged 30, was described as a "happy, gentle and compassionate soul, who was pursuing a career in medicine" and had a keen love for surfing and cricket.

"They were young men enjoying their passion of surfing together," Debra said. "Now it is time to bring them home to family and friends and the ocean waves in Australia."

Rhoad was engaged and set to marry Natalie Weirtz on Aug. 17 in Columbus, Ohio, according to a Zola online wedding registry. A GoFundMe which was launched to "rally support for Natalie" had raised over $80,000 as of Thursday morning.

"In the wake of the heartbreaking loss of Carter Rhoad, Callum Robinson, and Jake Robinson, our hearts ache with grief for their families, friends, and community," reads a separate GoFundMe set up for Rhoad's family.

In:
• Mexico
• Murder