The brother of US news presenter Savannah Guthrie has renewed his family's plea for proof that their mother is still alive after she disappeared last weekend. As the first deadline from an alleged ransom letter passed, Camron Guthrie said in a video posted to Instagram that the family had not heard anything about their missing mother, Nancy Guthrie.

The 84-year-old is believed to have been abducted from her home in Tucson, Arizona in the middle of the night. Police launched a massive hunt, with officials offering a reward of $50,000 for information that leads to an arrest.

We have to know that you have our mum, Camron said in the latest video message. We want to talk to you.

The family has expressed their distress at the lack of communication regarding Nancy's whereabouts. We haven't heard anything directly, he added, urging anyone with information to reach out to them. A briefing by the FBI confirmed they were reviewing an alleged ransom note that set a deadline for payment without detailing the consequences of noncompliance.

The case has sparked national interest, drawing reporters to the quiet community where Nancy lived, and Pima County Sheriff Chris Nanos stated investigators are working under the belief that Nancy is still alive. Authorities continue to gather information and urged the public to assist by reporting any leads to the sheriff's office, emphasizing the importance of dispelling misinformation surrounding the case.