US authorities investigating the disappearance of Nancy Guthrie have carried out new searches around her Arizona property following the emergence of a video that may be crucial to the case.

The video, obtained by American media organisation TMZ, appears to show a person wearing a jumper and carrying two backpacks about 8km from Guthrie’s home on the morning she was reported missing.

One of the backpacks appears to have reflective pieces similar to those seen in official FBI footage.

However, authorities have not yet confirmed the video’s authenticity or relevance to the investigation.

Investigators returned to Guthrie’s home on Thursday, local time, erecting a tent at the front door.

The area has been a focal point of the investigation, as it’s where Guthrie’s blood was discovered and where a doorbell camera captured images of a masked, armed figure on the morning of her disappearance.

Guthrie’s daughter, US TV star Savannah Guthrie, has shared a touching tribute to her missing mother, featuring a home video of her and her siblings as children from decades ago, vowing the family will never give up on finding their mum.

“Our lovely mum, we will never give up on her. Thank you for your prayers and hope,” Savannah wrote.

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On the 12th day of the mystery surrounding Guthrie’s disappearance, authorities continue to investigate thousands of leads, including a pair of gloves found near the 84-year-old’s home that could prove to be a crucial breakthrough.

Retired FBI Special Agent Richard Kolko earlier told Sunrise the gloves could be significant if they can be tied to a person seen in video footage at the home.

“Very important tip, very important lead. And that lead can go on to produce other leads,” Kolko said.

“One of the first things they’ll do is they’ll get that glove off to the lab. I’m sure it’s already there. They’ll check for any DNA, hair samples, even potentially a fingerprint.”

The investigation has generated an overwhelming response from the public, with 18,000 tips received in total, including 4,000 in the 24 hours after CCTV footage was shared.

Kolko explained investigators had used a triage system to process the flood of information, with teams working to evaluate every single tip.

“It’s basically like triage in a hospital room. They decide which ones are most important, where they need to go, and then they get them to that law enforcement agency so they can be acted upon as quick as possible,” he said.

“Especially while somebody is missing here and they want to try and find them alive.”

Investigators are working coast to coast on the case, with each lead potentially generating multiple new avenues of investigation.