A small detail in a ransom note claiming to be from Nancy Guthrie's kidnappers could reveal a key detail about the criminals.
As previously reported, the 84-year-old, who is the mother of TV news anchor Savannah Guthrie, was reported missing on February 1.
Nancy had vanished from her $1 million home in Tucson, Arizona, last weekend after being dropped off by her daughter and son-in-law, with the alarm being raised after she failed to arrive at church as expected.
A trail of blood was found outside her home, and the doorbell camera outside had also been removed in the early hours.
Her children - Savannah, Camron, and Annie - have since begged the captors to return their mother, who is without vital medication she needs daily.
Several ransom notes have surfaced since the disappearance, including one which police are taking seriously.
The alleged captors are demanding $6 million in bitcoin by 5PM on Monday, with a threat also being made to Nancy's life.
However, according to new reports, one small detail within the ransom note could suggest that the kidnappers are not in the US.
Reporter JJ McKinney, whose Arizona outlet KGUN9 was one of three to receive the ransom note, said per the New York Post: "Multiple ransom notes have been sent out to the media, including one that was sent to us.
"In the letter, the potential kidnappers demanded that the Guthries pay them $6 million before this Monday."
The purported kidnappers did not provide any proof of life or that they have Nancy, but included details from inside her house, which has prompted law enforcement to treat the demands as if they are real.
Nancy's children shared a video message to say: "We received your message, and we understand.
"We beg you now to return our mother to us so that we can celebrate with her. This is the only way we will have peace. This is very valuable to us, and we will pay.”
However, some experts have cast doubt on the ransom note, which specified that the ransom be paid in the equivalent of US dollars - which they believe could indicate that the person making the demand is not in the US, which could potentially mean it is a scam to obtain millions of dollars from the Guthries.
Former FBI agent Michael Harrigan told The New York Post: "If you’re domestic, why would you ever put ‘USD?’ You put 6 million.
"Why would you use that if you’re a domestic person? That points to somebody who might be potentially outside the country."
He added that that tiny detail "lends the potential for this being a scam."
No further communication has emerged from the supposed kidnappers as the deadline mentioned in their message draws closer.
Police have maintained a presence at Nancy's home and were seen searching a septic tank behind the property before leaving empty handed.