Shock new details emerge on how cops tracked down Mexican trio allegedly at centre of carjacking that killed Aussie brothers Jake and Callum Robinson

The girlfriend of a man accused of killing three tourists in Mexico was allegedly found with meth and one of the men’s phones after a routine stop.

The remains of Perth brothers Callum, 33, and Jake Robinson, 30, and their friend Jack Carter Rhoad, 30, were found dumped in a 45-metre deep well in Mexico’s Baja California province earlier this month.

Mexican authorities claim the perpetrators saw the trio’s Chevrolet Colorado and tried to steal the tires, killing the victims when they resisted.

Three Mexican nationals have been arrested; the alleged leader Jesús Gerardo, his brother Cristian Alejandro and Gerardo’s 23-year-old girlfriend Ari Gisel.

Gisel was stopped by police on May 1 during a routine patrol in Ensenada when she allegedly threw a bag containing 100 grams of meth on the ground and tried to run away. Telediario reported.

Jack Carter Rhoad, from the US, joined the Perth brothers on the surfing holiday in Mexico

Ari Gisel (photo) was arrested on May 1 after a routine patrol

An iPhone belonging to Mr Rhoad was also reportedly found during an inspection of the vehicle.

It was previously reported that Gisel had come to the attention of authorities after turning on Mr Rhoad’s phone, which then pinged a local mobile tower.

An investigator from Baja California said they had contacted U.S. authorities in San Diego to obtain the victims’ phone numbers.

“We tracked down the devices until one of them was turned on and we had a location,” they told The Daily Beast.

“Then we found this woman in possession of the American’s cell phone.”

Gisel previously told the court that Gerardo admitted to killing the three men after returning home on April 27 from the campsite where they were last seen alive.

The court heard Gerardo tell Gisel: “I basically ruined three gringos.”

Gisel asked what he meant by that, while Gerardo told her, “I killed them.”

She claimed he then showed her his car, which had sport tires allegedly stolen from the white Chevrolet Colorado the trio had been driving.

The prosecution now has the task of proving that Gisel was in possession of methamphetamine with the intent to sell the illegal drug.

Gerardo will remain in custody until his next hearing in November.

Mexican authorities reportedly discovered Mr. Rhoad’s iPhone and 100 grams of methamphetamine in Gisel’s vehicle during a patrol on May 1.

The remains were found in a pit (photo) more than 15 meters deep next to a cliff at Punta San José in Santo Tomás, in the municipality of Ensenada.

Baja California investigators previously said the trio was killed after their pickup truck was attacked by thieves.

“The tourists refused and tried to fight back, but the robbers were armed,” they said.

“When the criminals pulled out their weapons, the three [tourists] tried to de-escalate things but it was too late, they beat them and then shot them in the head.”

The brother’s parents, Martin and Debra Robinson, traveled to the region and spoke from San Diego, where they shared their heartbreak over the deaths of their sons.

“It is with heavy hearts that we share the news that Callum and Jake have been murdered,” Mrs Robinson said.

“Our hearts are broken and the world has become a darker place for us.

“We also mourn the loss of Carter Rhoad, a dear friend.

‘They were young men who enjoyed their passion together: surfing.

‘Now it’s time to take them home to family and friends – and to the ocean waves in Australia. Please live bigger, shine brighter and love harder in their memory.”

Baja California has been plagued by cartel violence in recent months.

In 2015, two Australian surfers, Adam Coleman and Dean Lucas, were killed in the western state of Sinaloa, across the Gulf of California from the Baja Peninsula.