A security guard made a gruesome discovery in Albuquerque, New Mexico, after the naked body of a man was found beheaded and castrated behind a local Walmart.

Officers tentatively described the victim as a 42-year-old while male but said they did not yet know his identity or where he is from.

The mutilated remains were discovered by a security officer behind a dumpster adjacent to the Walmart on Wyoming and Menaul Boulevards, in the north-east side of the city, on Saturday morning (17 December).

Police say they are still trying to locate the victim's family, being left to rely on fingerprint identification due to the missing head.

The cause of death remains unknown and police do not know if the suspected murder is related to drug cartels or gangs.

"It's tough. It's not something that's easy to see," Albuquerque Police Department spokesperson Fred Duran told local news channel KOB4. "I've been on scenes when I was working in the field that they're gruesome.

"You're walking through things you probably don't want to walk through. You're seeing stuff that you don't want to see, but it's part of our job."

Authorities believe the unidentified man was killed elsewhere and later brought to the Walmart.

Duran added: "We don't know the specifics of what happened or how the body got there. We do know that the incident did not occur at the Walmart. This seems like it was the end point of the contact between the person who did it and the victim."

Police said they are still seeking suspects connected with the death.

Anyone with information about the case is being urged to notify Albuquerque Metro Crime Stoppers.