A glove discovered as part of the investigation into Nancy Guthrie's kidnapping has produced no DNA matches, authorities in Pima County, Arizona, say.

Found approximately two miles from Guthrie's home, the glove appeared to match one that can be seen on the hand of a suspect in doorbell-camera footage taken the night she went missing.

DNA from the glove was sent for testing on Thursday, but produced no matches in CODIS, the FBI's database of DNA from known offenders.

Nancy Guthrie, the 84 year-old mother of news anchor Savannah Guthrie, has been missing since 1 February, when investigators believe she was taken from her home against her will. The family has made repeated pleas for her return.

The FBI said on Sunday that investigators recovered the glove from a field near the side of the road about two miles (3 km) from Guthrie's home in Tucson, Arizona.

The agency collected about 16 gloves from various locations near Nancy Guthrie's home, although most turned out to have been discarded by people searching for her.

Last week, investigators released video footage taken from a doorbell camera at Guthrie's front door that showed a masked man wearing gloves and a backpack.

In the video, the suspect walks toward the camera and tries to cover it with his gloved hand before grabbing some brush from the front yard to block the camera's view.

After conducting a forensic analysis of the video, the FBI said it believed the man was between 5ft 9in and 5ft 10in (175-177cm) tall with an average build.

More than two weeks since Guthrie was reported missing, no arrests have been made, the sheriff's department confirmed on Tuesday, adding that more DNA found in the home is being analysed.

Authorities also shared that they are working with Walmart to determine who purchased the backpack worn by the suspect in the video.

Police said over the weekend that the Guthrie family, including Nancy Guthrie's children and their spouses, are not suspects in her abduction.

Guthrie's three children have posted multiple videos pleading for their mother's safe return in the two weeks since her disappearance, saying they are willing to pay her abductors.

Over the weekend, Savannah Guthrie posted one addressing a potential kidnapper directly.

"It is never too late to do the right thing," she said. "We are here and...we believe in the essential goodness of every human being."

Guthrie was last seen on the evening of 31 January, when a family member dropped her off at her home following a get-together at her daughter Annie Guthrie's house.

Members of her church noticed her absence the following day and notified her family.

A massive search operation has involved both the Pima County Sheriff's Department and the FBI, who have been combing through Guthrie's home and the surrounding areas.

Officials have warned that Guthrie needs regular medication and is "not in good physical health". They have said she has no reported cognitive issues.

Police have also found blood on the floor of Guthrie's porch - which was confirmed to be hers.

The FBI has increased the reward for information about her disappearance from $50,000 (£36,700) to $100,000.