Savannah Guthrie and her siblings have demanded that anyone holding her mother, Nancy Guthrie, provide proof of life in a heartbreaking new video.

“We, too, have heard reports about a ransom letter in the media. As a family, we are doing everything that we can. We are ready to talk,” Savannah said in the video posted to Instagram Wednesday night. “However, we live in a world where voices and images are easily manipulated. We need to know, without a doubt, that she is alive and that you have her.”

Nancy vanished from her Arizona home Saturday night. Local authorities believe she was abducted in her sleep.

This is a developing story…