A missing Covington man found dead in a burned-out car had been suffocated, authorities said Thursday.

Gregory Vernon Harris' body was found nearly two weeks ago in the trunk of his car after firefighters extinguished the burning vehicle in southwest Atlanta, police said.

Thursday, after informing his immediate family, investigators with the Fulton County Medical Examiner's Office said Harris, 49, died of asphyxiation from being suffocated, and ruled his death a homicide.

Harris was reported missing from his Covington home on July 13, Newton County police said. According to the missing person's report, his sister told police that his belongings had been tossed about inside his home.

Around 2:30 a.m. the next day, Atlanta firefighters responded to a fire at a home in the 800 block of Westmont Road. They found the Infiniti M35 registered to Harris set ablaze, along with the abandoned house the car was parked behind, police said.

Using dental records, authorities last week identified the body found in the trunk as Harris.

It is unclear where, when or why Harris was killed.

Atlanta homicide detectives and Newton County police continue to investigate.