United Kingdom, July 2 -- The FBI have received "several" ransom notes related to Nancy Guthrie's disappearance and believe some "may potentially be legitimate".

The 84-year-old mother of Today host Savannah Guthrie went missing from her Arizona home in the early hours of 1 February and her whereabout are still unknown, with no suspects have been identified, but authorities are still investigating a number of leads.

Last month, a ransom note sent to a US TV station suggested Nancy had died shortly after being abducted but it was later reported that the contents of a few notes which had been made public were deemed to be fake, a claim the FBI have now responded to.

The agency confirmed that while somemessages have been deemed "extortion...