Aniah Blanchard, 19, who has been missing since Oct. 23, "is considered to be a victim of foul play," police said, as to Fox 6 reported.
Dana White, president of the mixed martial arts fighting league, tweeted a video saying he was offering a $25,000 reward in the search for Blanchard, a student at Southern Union State Community College and the stepdaughter of UFC fighter Walt Harris.
The money by White was in addition to a $5,000 reward offered by the state of Alabama. In a statement, the governor’s office said the money was being offered for information leading to an arrest and conviction in the teen’s disappearance.
Blanchard was last seen a week ago in Auburn, Ala., and police later found her damaged car in Montgomery, about 55 miles away.
The vehicle – a black 2017 Honda CR-V – wasn’t damaged before she disappeared, police said.
A video released Monday by police showed Blanchard in a store in Auburn the day she was last seen.
“This is a criminal investigation, obviously we’re approaching it as such,” Lee County District Attorney Brandon Hughes said at a news conference Wednesday. “We do not believe that Aniah would or did go missing on her own volition.”
The FBI, U.S. Marshals Service, the Department of Homeland Security and other law enforcement agencies have joined the investigation.
Harris and other relatives have issued pleas for information about her whereabouts. Capt. Lorenza Dorsey, an Auburn police spokesman, said investigators weren't eliminating any possibilities in the search for Blanchard.
"We're hopeful, but we're extremely concerned because of the amount of time that's now passed," Dorsey said.
Anyone with information is asked to call the Auburn Police Division Detective Section at 334-501-3140, the anonymous tip line at 334-246-1391, the 24-hour non-emergency number at 334-501-3100, or their local police.
The Associated Press contributed to this report.