The search for Nancy Guthrie has entered a new phase as investigators explore whether data from her heart pacemaker could help uncover clues about her disappearance.

Guthrie who is the mother of television host Savannah Guthrie, was reported missing on February 1 after family members were unable to contact her.

According to authorities she had been dropped off at her home in Arizona the night before. When relatives were unable to reach her the following day they contacted police triggering a large search operation.

Now investigators are reviewing whether the Bluetooth signal from Guthrie’s pacemaker could help narrow down her last known location. Medical experts say some pacemakers can connect to smartphones to transmit health data which may provide limited clues.

Specialised tools are being used to determine if any signal linked to the device can still be detected.

Dr. Laurence Epstein of Northwell Health explained that while pacemakers can communicate with nearby devices they are not designed to work as GPS trackers and have a very limited range.

Officials said the connection between Guthrie’s pacemaker and her phone ended on February 1 when the two devices were no longer close to each other.

Police have also released doorbell camera footage that appears to show a masked person standing on Guthrie’s porch around the time she disappeared.

Investigators believe the individual could be a man carrying a black backpack though authorities have not identified the person and no arrests have been made so far.

The investigation remains ongoing as authorities continue to examine possible leads in hopes of locating Guthrie.