A prosecutor in Mexico has asked for jail sentences of more than 200 years for the men accused of murdering Australian brothers Jake and Callum Robinson during a surfing trip last year.

Jake and Callum Robinson, along with their American friend Carter Rhoad, were killed while camping and surfing in Baja California, Mexico in April last year.

Jake, a 31-year-old doctor from Perth, had travelled to the US to meet his brother Callum, 32, who had lived there for more than a decade. Their bodies were found with gunshots to the head, execution-style.

Jesús Gerardo, Irineo Francisco and Ángel Jesús, the three men who were all charged with aggravated homicide, appeared in court on Friday in the city of Ensenada.

Prosecutor Raúl Cobo Montejano requested 210-year sentences for the three men. He also asked for an extra 168 years for Jesús Gerardo, who faces an additional charge of forced disappearance.

All three defendants rejected plea deals that would have seen them serve between 47 and 52 years in prison. Their trial date is yet to be set.

They are also charged with aggravated robbery, violent robbery and grand theft auto.

Jesús Gerardo’s ex-girlfriend Ari Gisell, also faced court. She was first seen as a cooperative witness and helped authorities track down the accused men, but was later charged with offences including inciting robbery, though not murder.

She rejected a plea offer that included a 20-year sentence, and her case has been adjourned until November 19.

Family members of the victims watched the hearing by video link, while representatives from the Australian embassy also attended remotely.

The prosecutor also told the court that authorities are still searching for another man believed to have been involved in the killings. He said investigators know the suspect’s nickname, but it has not been released.

Cobo Montejano added that the case is based on evidence from about 35 witnesses, along with forensic material.

Speaking outside court, he said he expected the trial to be lengthy, and noted that some witnesses are foreigners who may need to return to Mexico to testify.

He said prosecutors do not know who fired the fatal shots.

Authorities have previously said the killings were linked to a tyre robbery that went wrong, and that they do not believe criminal cartels were involved.

However, court documents revealed in July alleged that Jesús Gerardo and Irineo Francisco had links to Mexico’s Sinaloa cartel.

The accused men are being held in high-security El Hongo prison in the Mexican desert, after being moved from a local jail due to concerns over their alleged cartel connections.

Ángel Jesús and Ari Gisell are being held in a lower-security facility in Ensenada.

The full names of the defendants have been withheld under Mexican legal conventions.

Images: Instagram/ Mexican Police Handout