An infamous Los Angeles cop-turned-killer’s handgun popped up during an investigation into a $1 million armed robbery in Beverly Hills.

Two South American nationals — allegedly part of a gang targeting tourists in the Los Angeles area — were charged Tuesday with stealing a $1 million Patek Philippe watch from a man at gunpoint as he dined with his family on the patio of the Beverly Wilshire Hotel on Aug. 10, the US District Attorney’s Central District of California Office reported.

Prosecutors revealed that law enforcement was able to track down the location where the alleged perps were staying to an Airbnb in Exposition Park — about 10 miles away from the 90210 hotel.

Police then executed a search warrant at the property Saturday morning, where they found the handgun registered to deranged former Los Angeles Police Department officer Christopher Dorner.

Dorner is notoriously known as the disgruntled former cop who sparked a 9-day manhunt in 2013 — when he gunned down four people — including a fellow police officer — and wounded three others in targeted attacks. 

The incident ended with Dorner taking his life during a shootout with law enforcement at a cabin in the San Bernardino Mountains. 

Prior to his murderous rampage, Dorner claimed he was unfairly fired as an LAPD officer and vowed to take revenge against law enforcement officers in a bizarre manifesto posted on his Facebook.

The Glock 21 .45 caliber handgun, which once belonged to the cop killer, was found tucked away inside a pillowcase when officers raided the property, according to prosecutors.

It is unclear how the suspects came into possession of Dorner’s firearm or if the gun was used during the robbery of the Patek Philippe.

The Homeland Security Investigations, the Beverly Hills Police Department, and the Blythe, California Police Department are investigating, prosecutors said.

Hours after searching the Airbnb, police conducted a traffic stop on a Chevrolet Equinox, during which the two suspects of the armed robbery, Jamer Mauricio Sepulveda Salazar, 21, and Jesus Eduardo Padron Rojas, 19, were arrested.

The SUV was allegedly linked to another armed robbery in Beverly Hills on Aug. 5, during which a $30,000 Rolex was stolen, according to prosecutors.

“We will not accept violent crime perpetrated by organized crime groups that exploit the freedoms of our country,” said Attorney Martin Estrada.

“Our number one mission is to protect our community and those who undermine public safety will be held accountable.  We should all be grateful for the swift actions of law enforcement in apprehending these suspects before they could cause more harm.” 

Sepulveda — a Columbian national — has been charged with one count of interference with commerce by robbery and one count of possessing a firearm in furtherance of a crime of violence, according to prosecutors.

Padron, a Venezuela national, was charged with one count of conspiracy to commit robbery.

If found guilty on all counts, Sepulveda could face life in federal prison.

If found guilty of the conspiracy charge, Padron could face up to 20 years.

Both men’s arraignment are scheduled for September in the United States District Court in downtown Los Angeles.