Officials have “good reason” to believe human remains found in Alabama belong to the missing stepdaughter of a UFC heavyweight fighter.

The remains were found on a county road in Macon County, Lee County district attorney Brandon Hughes told the Associated Press.

“I can confirm that human remains have been found in Macon County on County Road 2 and we have good reason to believe they are that of Aniah Blanchard,” Mr Hughes said.

Police have arrested three people over the disappearance of the 19-year-old, who was last seen on October 23 in Auburn. Her stepfather is UFC fighter Walt Harris.

After she disappeared, her black Honda car was found abandoned more than 50 miles away at an apartment complex in Montgomery, Alabama.

Auburn police detective Josh Mixon said Ms Blanchard’s blood was found in the car and it appeared she had suffered a life-threatening injury.

Mr Mixon said convenience store video footage showed a man buying a beverage look over at Ms Blanchard.

He said sources later identified the man as Ibraheem Yazeed, 29, and a man at the store told investigators he saw Yazeed force Blanchard into her car and drive away.

Ibraheem Yazeed in court
Ibraheem Yazeed in court (Hannah Lester/Opelika-Auburn News/AP

Police have arrested Yazeed and a second man, 35-year-old Antwain Shamar Fisher, of Montgomery.

In an arrest warrant filed with the court on Monday, police said Fisher helped Yazeed by disposing of evidence and driving him.

Mr Hughes said a third man, David Johnson Jr, was arrested on Monday in Montgomery and charged with hindering prosecution in the case.

The discovery of human remains came after a month-long search for the missing teenager whose face appeared on billboards across the county.

Auburn Police said on Monday that investigators “obtained information regarding the possible location of a body”.

Law enforcement officials searched a wooded area in Shorter, Alabama, and found what appeared to be human remains several feet into the woods.

“A complete investigation is under way… to determine the identity and how the victim came to be at that location. The examination will explore if the remains are those of Aniah Blanchard,” Auburn police said in a statement.