Major update in effort to bring home two Australian brothers Jake and Callum Robinson after they were killed in Mexico - as their family make a significant step

The bodies of murdered Perth brothers Callum and Jake Robinson have been moved into the United States, beginning their journey home after they were killed in an attempted carjacking in Baja California. 

The brother's deaths sparked an outpouring of grief after they disappeared on April 27 while on a surfing trip in the northern Mexican state. They were found at the bottom of a well a week later.

Callum and Jake's American friend Jack Carter Rhoad was also killed.

On Friday the men's bodies were moved to a funeral home in San Diego, with the bodies are expected to then be transferred back to Perth.

The news comes after the infamous Sinaloa Cartel claimed it 'handed' over the alleged killers of the men. 

Jesus Gerardo Garica Cota, also known as 'El Kekas', along with his brother Cristian Alejandro and girlfriend Ari Gisel have since been arrested by Mexican authorities.

But in a stunning twist the ­Sinaloa Cartel - one of the most powerful drug syndicates in the criminal underworld - broke its silence over the trio's deaths and claimed it had turned the alleged killers in.

A cartel member said the three were not part of the cartel.

'They were low-level robbers acting alone,' the anonymous member told US outlet The Daily Beast. 'But we handed them over.

'We learned that the cops were looking for the gringos and also began looking for those who were responsible. We called the authorities to let them know where to find them.'

The cartel member said the criminal organisation was afraid of getting 'unwanted attention' from Mexican authorities.

It follows Gerardo fronting a Ensenada court this week, where prosecutors revealed Ms Gisel had become a key witness in the case.

So far prosecutors have only charged Gerardo with forced kidnapping but this is expected to be upgraded to murder.

Nine News correspondent Alison Piotrowski, who was in the courtroom for the hearing, told 2GB on Thursday it was alleged that Gerardo had told Ms Gisel he 'f. ked up three gringos'.

The court heard she had asked, 'What do you mean?' to which he replied, 'I killed them.'

Baja California's Attorney-General, Maria Elena Andrade Ramirez, said prosecutors would allege the foreigners were confronted by the Mexican nationalists who intended to rob the trio.

'In response to the victims' ­reaction, they deprived them of their lives,' a statement from her office read.

'Through the investigations carried out ... the white Chevrolet Colorado vehicle in which the victims were travelling was found burned.'

Jake and Callum's parents formally identified the brothers' bodies in Mexico this week.

Ms Robinson on Tuesday paid tribute to the pair, saying the world had ­become 'a darker place' for them and that their hearts were broken.

'We also mourn the loss of Carter Rhoad, a close friend. They were young men enjoying their passion of surfing together,' Ms Robinson said.

'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.'

She also thanked those who had offered their condolences and said they had been 'overwhelmed with the outpouring of emotions and support'.

'We have always been very proud of their academic and sporting achievements and ­admired their life choices as,' Ms Robinson said.