The Federal Bureau of Investigation has amassed as many as 10,000 hours of video in the investigation into the disappearance and possible abduction of Nancy Guthrie, an FBI official said Thursday.

The official described the collection, review and analysis of video as one of the key parts of the weekslong investigation, which began after the 84-year-old mother of “TODAY” co-anchor Savannah Guthrie was reported missing Feb. 1.

Tools can be used to enhance the videos, but each one must be watched in real time, the official said, noting that slowing them down or enhancing them takes more time.

The official said that additional canvassing was done last week to gather more material from camera systems in the Tucson-area neighborhood where Guthrie lives.

The FBI released a widely circulated security video two weeks ago showing a masked, armed man with a backpack appearing to tamper with a Google Nest doorbell camera at Nancy Guthrie’s home.

Authorities have described the man as a suspect but he has not been publicly identified. Pima County Sheriff Chris Nanos has said investigators believe Guthrie was taken from her Tucson-area home, possibly in the middle of the night.

She was last seen around 9:45 p.m. Jan. 31 after dinner at her daughter Annie Guthrie’s home, Nanos has said. She was reported missing after failing to show up at a friend’s house to watch a virtual church service.

Savannah Guthrie announced Tuesday that her family is offering a reward of up to $1 million for the recovery of her mother.

“Please keep praying without ceasing,” she said in an Instagram video. “We still believe. We still believe in a miracle. We still believe that she can come home, hope against hope. As my sister says, ‘We are blowing on the embers of hope.’”

FBI Director Kash Patel has said the images from the Nest camera were recovered from “residual data in backend systems” because Guthrie did not have a subscription that would have saved the video.

Patel said the images were captured the morning Guthrie disappeared. Two law enforcement sources told NBC News this week that one of the images released by the FBI director was captured earlier.

The agency has declined to comment on possible dates linked to the image, which shows a masked man without a backpack. The Pima County Sheriff’s Department has said that any suggestion that it was taken on a different day is “purely speculative.”

Authorities are examining other potential evidence in the case, including DNA collected from Guthrie’s home and related search locations. Pima County Sheriff Chris Nanos has said authorities may use genetic genealogy — a forensic tool that combines advanced DNA analysis with traditional genealogical research — in the investigation.