One of the suspects in the triple murder of two brothers and their friend while they were in Mexico to surf last month allegedly confessed to the grisly killing, according to court testimony.

Jesús Gerardo Garcia Cota allegedly showed up at his girlfriend Ari Gisel García Cota’s house on April 28 and told her he did something to “three gringos,” the girlfriend testified on Wednesday, according to the BBC.

Asking what he meant, the Garcia Cota told Ari Gisel “I killed them.”

He made the stunning admission on April 28, the day after Australian brothers Jake and Callum Robinson, 30 and 33, and their American friend Jack Carter Rhoad, 30, were last seen alive in the city of Ensenada in the Mexican state of Baja California where they had met up for a surfing trip.

After the confession, Ari Gisel said her boyfriend brought her out to her car, which he’d outfitted with new tires allegedly pilfered from the victims’ pick-up truck.

Mexican prosecutors alleged the suspects were trying to steal the victims’ tires and gunned the surfers down when they tried to resist the bandits.

The surfers’ bodies were found dumped down a 50-foot well in early May, about a week after they went missing. Each had gunshots to the head and were found alongside a fourth body officials believe had been in the well before they were dumped and was unrelated to their killing.

A white pickup truck similar to the one they’d been driving was also found torched nearby.

The trio had traveled to Ensenada for a trip of surfing and camping down the Baja California coast — which has recently been embroiled in a turf war between rival gangs — after partying at Coachella.

Despite the apparent confession about the tires, some have cast doubt on the official narrative of the killings in light of the recent gang activity.

“My guess is they were mistakenly identified as a rival criminal organization and murdered, a source working in private security in Mexico recently told The Post.

“That being exposed would create an ongoing investigation that no cartel wants to deal with and would create a devastating impact on tourism in the area.”

In addition to Garcia Cota and his girlfriend’s arrest, his brother Cristian Alejandro Garcia was also arrested. Each allegedly had meth on them when they were arrested, according to reports.

Mexican prosecutors allege the victims’ were killed trying to fend off the suspects.