Authorities in Tucson said a human bone found near Nancy Guthrie's Arizona home was not connected to her disappearance and is being treated as part of a prehistoric anthropological investigation.
The bone was discovered on May 7 near North Craycroft Road and East River Road, roughly seven miles from Guthrie's home in the Catalina Foothills area.
Tucson police said the find was examined with help from the University of Arizona's anthropology department and the Pima County medical examiner's office. The bone was located by a livestreamer who was searching the area for possible clues in the case, according to Entertainment Weekly.
Guthrie, the 84-year-old mother of "Today" co-anchor Savannah Guthrie, was last seen the night of Jan. 31 after her son-in-law dropped her off at her home. Family members reported her missing the next day after she did not appear for a virtual church service.
Authorities have treated the case as a suspected abduction since early in the investigation.
Investigators say a masked person was captured on a Nest doorbell camera at Guthrie's home in the early hours of Feb. 1. The FBI later recovered the video from backend data after the camera was damaged, and the footage showed a person wearing a balaclava, gloves, and a backpack.
Officials also said Guthrie's blood was found outside the home, and that mixed DNA from at least one male was recovered from the scene, but has not been matched to any individual.
Among the investigative leads explored is the possibility that Guthrie was transported across the border into Mexico, roughly 60 miles from her Tucson home, the BBC reported.
The FBI contacted law enforcement in Sonora, the Mexican state bordering Arizona, and briefed U.S. Border Patrol agents on the case as part of standard investigative procedures, though officials stressed there is no confirmed evidence she crossed the border.
In April, TMZ received a letter from an anonymous source claiming the writer had seen Guthrie alive with kidnappers in the Mexican state of Sonora, though investigators have not publicly confirmed the claim.
A ransom note received earlier in the investigation demanded approximately $6 million in cryptocurrency, and authorities also examined genetic genealogy as a possible avenue to identify the suspect.
No suspect has been publicly named, although authorities briefly detained one man in February and later cleared him. The FBI has received more than 13,000 tips, and a reward of more than $1.2 million is being offered for information that could help find Guthrie, as per Fox News.
