Pima County's sheriff has pushed back against claims that a masked suspect captured on Nancy Guthrie's doorbell camera may have visited her Tucson home on two different days before her suspected abduction on 1 February.

A source with knowledge of the investigation told Fox News Digital that one of the Nestdoorbell images released by the FBIwas recorded on a different date from the others, suggesting the suspect may have scouted the property in advance.

However, Sheriff Chris Nanos said the information did not come from his office, and his department later described any such conclusions as 'purely speculative'.

Authorities in Arizona are trying to piece together what happened to Guthrie, 84, who is the mother ofTodayhostSavannah Guthrieand has been missing for more than three weeks. Detectives are working with the FBI and have appealed repeatedly for footage from neighbours' security cameras to help establish the suspect's movements.

The unnamed source cited by Fox News Digital on Monday declined to say exactly when the earlier image was recorded, citing the ongoing nature of the investigation. ABC News had previously reported, also citing unnamed sources, that the armed suspect appeared on Guthrie's porch on more than one occasion.

Images released by the FBI show a masked individual on the 84-year-old's front step, including one frame in which the person appears to be tampering with the camera.

In some images, the suspect is wearing a backpack and a holstered gun; in others, those items appear absent.

A spokesperson for the Pima County Sheriff's Department (PCSD) said differences in the suspect's attire were known to investigators, but insisted there were no official timestamps on the stills made public.

'We are aware that doorbell images released earlier in the investigation depict a suspect in different stages of attire, including with and without a backpack,' the PCSD said in a written statement. 'There is no date or time stamp associated with these images. Therefore, any suggestion that the photographs were taken on different days is purely speculative.'

The FBI has not publicly confirmed whether any of the images were captured on separate dates and did not immediately respond to a request for comment.

Source: International Business Times UK