TUCSON, Ariz. (AP) — The urgent investigation into the apparent kidnapping of 84-year-old Nancy Guthrie continued Sunday, a week after the mother of “Today” show host Savannah Guthrie was reported missing in Arizona.

Savannah Guthrie solemnly told the potential kidnappers in a social media video released Saturday that the family was prepared to pay for her safe return. Flanked by her siblings, Guthrie said “we received your message” and that: “This is the only way we will have peace. This is very valuable to us, and we will pay.”

An FBI spokesman stated that Savannah Guthrie was referring to a message sent to the Tucson-based television station KOLD on Friday. However, the station declined to provide details about the message as the FBI conducted its review.

Investigators believe Nancy Guthrie was taken against her will from her home just outside Tucson last weekend. DNA tests showed blood on Guthrie’s front porch matched her DNA, as confirmed by Pima County Sheriff Chris Nanos.

Multiple press outlets have received alleged ransom letters throughout the week. At least one letter included monetary demands and set deadlines for Thursday evening and Monday evening. Law enforcement officials indicated they could not confirm the letters' credibility but stressed that all tips were being treated seriously.

The sheriff’s office did not respond to requests for updates Sunday morning, but a spokesman for the FBI confirmed the investigation was ongoing.

The disappearance of the well-known TV host’s mother has fixated Americans over the past week. Candles remained lit early Sunday near Nancy Guthrie’s home, next to a sign expressing support for the family.

The White House stated President Donald Trump reached out to Savannah Guthrie last week, indicating that he believed there were strong clues in the case.

Authorities expressed growing concern for Nancy Guthrie’s health due to her need for daily medication. Reports suggest she has a pacemaker and has a history of high blood pressure and heart issues, as noted in audio recordings from sheriff’s dispatch.

The video released Saturday was the third plea for help by the family this week.