Nancy Guthrie was abducted by force from her home in the Catalina Foothills neighborhood in northern Tucson around 2:30 a.m. on Feb. 1, according to Pima County Sheriff Chris Nanos.
The FBI has already announced a $50,000 reward for information leading to her recovery or the arrest of anyone involved.
A purported ransom note sent to TMZ last week contained information indicating Nancy Guthrie may not be in Tucson, Ariz., the outlet reported.
TMZ's Harvey Levin said that information in the ransom note has information stating that Guthrie is somewhere on the West Coast or possibly in northern Mexico.
"We are encouraging anyone with information to contact the FBI through 1-800-CALL-FBI. No tip is too small!" the FBI spokesperson told Fox News.
Fox News’ Melissa Summers, Michael Ruiz and Adam Sabes contributed to this report.