India, June 29 -- Retired FBI special agent Jason Pack believes the anonymous person who has repeatedly emailed TMZ about the disappearance of Nancy Guthrie could hold crucial information for investigators, regardless of who they claim to be.

Pack's comments came after TMZ reported that it had received a new letter from somebody who had previously contacted the outlet.

The latest message allegedly claimed the sender possessed video showing the person who abducted Nancy and footage from the day she reportedly died. TMZ said it forwarded the email to the FBI. Authorities have not publicly confirmed the authenticity of the claims or announced any breakthrough.

Nancy Guthrie, 84, the mother of NBC Today co-anchor Savannah Guthrie, disappea...