A southern Colorado funeral home operator, known for performing "green" burials, is under investigation for improper storage of human remains inside one of its properties, authorities said Thursday.

Fremont County Sheriff’s Office deputies responded to a report of a "suspicious incident" on Tuesday evening at a funeral home in Penrose, Colorado, a small town about 34 miles southwest of Colorado Springs. The following day, authorities executed a search warrant on the property and discovered "improperly stored" human remains inside the building, the sheriff's office said in a news release Thursday.

The sheriff’s office said it was working with several state and federal agencies in the investigation.

The Penrose property was owned by the Return to Nature Funeral Home, which is based in Colorado Springs, according to authorities. The family-owned and operated funeral home performs what they describe as green or natural burials without embalming chemicals or metal caskets.

The sheriff's office is also asking family members of decedents who have utilized the Return to Nature Funeral Home and individuals who have any potential information related to the investigation to contact authorities. The Colorado Bureau of Investigation told USA TODAY on Thursday that the agency did not have any further information.

Under Colorado law, green burials are legal but state code requires that any body not buried within 24 hours must be properly refrigerated. The investigation is the latest incident involving funeral home operators in Colorado.

In January, two Colorado funeral home operators were sentenced to prison for illegally selling body parts and bodies, and giving clients fake ashes.

When the dead don't stay buried:The grave situation at cemeteries amid climate change

Residents, businesses detected foul odor near funeral home

Several law enforcement agencies were investigating the Penrose property, a single-story building with a parking lot surrounded by overgrown weeds, on Thursday.

Trash bags could be seen outside the entrance of the building and a hearse was parked in the back. Two law enforcement vehicles were parked in front with yellow police tape closing off the area as a foul odor permeated the air.

Joyce Pavetti, 73, lives near the funeral home and can see the property from the stoop of her house. She told the Associated Press that she caught whiffs of a putrid smell in the last few weeks.

“We just assumed it was a dead animal,” she said. On Wednesday night, Pavetti said she saw lights from law enforcement as they swarmed around the building.

Different businesses have occupied the building over the years, according to Pavetti, who once took yoga classes there. But Pavetti said she hadn't seen anyone on the property recently and only noticed the hearse behind the building in the last few months.

Other residents and nearby businesses also reported smelling the odor coming from behind the building. James Glidewell, who works on a property behind the funeral home, told The Colorado Springs Gazette that he had smelled the odor for at least a month.

"I'd randomly smell it, but I didn't think anything of it. I thought it was just roadkill or something like that," he told the newspaper. "Every time you'd drive by here, you'd smell it.”

Glidewell also noted that the funeral home appeared to be vacant until two vehicles were seen parked on the property's parking lot in June, The Gazette reported.

Hearts, brains and bones:Stolen body parts scandal stretches from Harvard to Kentucky

Return to Natural Funeral Home declared delinquent

The Return to Nature Funeral Home provides burials of non-embalmed bodies in biodegradable caskets, shrouds or "nothing at all," according to its website. The operator charges $1,895 for a green burial, which doesn’t include the cost of a casket and cemetery space.

"No embalming fluids, no concrete vaults. As natural as possible," the funeral home's website states. Return to Nature was established six years ago in Colorado Springs, according to public records.

The funeral home did not immediately respond to USA TODAY's request for comment.

Online records from the state Department of Regulatory Agencies show that the Penrose funeral home was owned by "Hallfordhomes LLC." The company's funeral home license was originally issued on March 25, 2019, and was effective as of Dec. 1, 2021, but expired on Nov. 30, 2022, records show.

The company also owns a business with a Colorado Springs address which the Colorado Secretary of State declared delinquent on Oct. 1 for failing to file a routine reporting form that was due at the end of July. According to Fremont County records, the company had changed addresses three times in the Colorado Springs area since its establishment in 2016 with a post office box.

County records show that Hallfordhomes still owes about $5,000 in 2022 property taxes for its Penrose building.

Contributing: The Associated Press