Investigators hope the notes' "distinct linguistic characteristics" may be recognised by a member of the public.

Nancy Guthrie (left) is the mother of Savannah Guthrie (right), one of the most recognisable TV presenters in the US Police in Arizona have released two ransom notes in the hope the public can help identify whoever abducted the mother of US news presenter Savannah Guthrie. The first note, which is treated as apparently credible, demanded millions of dollars in Bitcoin. The other claimed Nancy Guthrie died shortly after she was abducted from her home near Tucson six months ago. The Pima County Sheriff's Office say they cannot verify her death, and the investigation remains active. Officials released the two notes on Friday, asking the public for help identifying the writer, whose "distinct linguistic characteristics may be recognisable". Investigators believe that Nancy Guthrie, who was aged 84 when she was last seen on 31 January, was taken against her will from her home, but they have not shared a possible motive or arrested a suspect. The notes were addressed to Savannah Guthrie and the Guthrie family, and sent to a local TV station in Tucson, Arizona, in the days after Nancy Guthrie disappeared, according to the sheriff. "A friend, family member, coworker, classmate, or acquaintance may recognise these patterns of expression and possess information that could help identify the individual responsible," the sheriff's office said in a statement.