A MASKED man may have visited Nancy Guthrie’s home in the days leading up to her kidnapping, it has now been claimed.

Images released by cops appear to show a man in two different outfits, leading to speculation that the pictures were taken over several days.

The FBI released surveillance footage earlier this month of a man in a mask with a backpack, who appeared to be holding a gun, on the night Nancy disappeared from her home.

A second image – where the man does not appear to have his backpack or gun – has now led to suggestions some of that footage was captured in the days before she was taken.

A source told ABC News one theory is that that the suspect originally went to the home for a first time, noticed the camera and was scared off – leaving the scene.

He then reportedly came back – which is when he is seen tampering with the device and putting branches in front of the lens.

Police would not be drawn on when exactly the footage was captured, according to Fox.

But investigators have asked neighbors to check their home security systems for suspicious people and vehicles going back as far as January 1 – a whole month before the abduction took place.

They said in a statement: “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.

“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.

“This remains an active and ongoing criminal investigation.”

Stalled investigation

Nancy was last seen at her Arizona home on January 31. She was reported missing by her family on February 1.

Since then, 400 investigators have been assigned to work on the case 24/7.

But a lack of recent progress in finding the 84-year-old may mean resources are cut in the coming days, a source told ABC News on Friday.

Leads on the man seen in chilling surveillance footage have so far not proved fruitful.

So far, no suspect has been identified in Nancy Guthrie’s disappearance.

Jason Pack, a former FBI agent, told ABC News that if it is the same person, “it could indicate that the person was there surveilling the place before the abduction happened.”

“The fact that there was preparation and planning, which makes it more of a sophisticated type of criminal activity than someone just showing up,” he said.

As the investigation continues, Savannah Guthrie announced on Tuesday that her family would offer a $1million reward for information leading to the return of her mother.