(NewsNation) — As the search for Nancy Guthrie continues, new details have emerged about anonymous tips claiming she is “buried with nature now.”

A volunteer search group in Mexico, Buscando Corazones Nogales, has been investigating those claims after receiving what it says were two anonymous tips. The first, received May 10, alleged that a body matching Guthrie’s description was buried in a shallow grave about 70 miles from her Tucson, Arizona, home. A second tip reportedly provided additional information.

Despite the group’s efforts, Guthrie has not been found.

Authorities do not appear to be placing significant weight on the group’s claims. Investigators have not participated in the searches, and officials in Mexico have said they found no credible information linking Guthrie to the area.

Nancy Guthrie search: Buscando Corazones Nogale finds 25 bodies

What has drawn attention, however, is the group’s claim that it has uncovered 25 unmarked graves during its search efforts.

Retired FBI agent Maureen O’Connell told NewsNation’s Brian Entin that while cartels are known to dispose of victims in remote areas, there is currently no evidence connecting Guthrie’s disappearance to cartel activity.

O’Connell suggested the group’s efforts may be focused on identifying remains found in the area. She noted that DNA testing in Mexico can be more difficult because fewer people participate in genetic databases, making it harder to match remains with missing persons.

“There are a lot of moving parts here,” O’Connell told the “Brian Entin Investigates” podcast. “They may be looking for money to get DNA tests so that family members that have that have missing loved ones can find out if one of if the one of these sets of remains belongs to them, so they can give them a proper burial.”

FBI vet questions credibility of tip in Nancy Guthrie investigation

As for the claim that Guthrie could be among the remains, O’Connell said that theory would require evidence that she was targeted by a criminal organization, something investigators have not publicly suggested.

O’Connell also questioned the credibility of the anonymous tips, saying law enforcement would want to examine exactly where the information originated.

“If someone says they received a tip, investigators are going to want to see it,” she said. “Was it a text message, an email, a website submission? If there is no record of the tip, then you have to ask what you’re basing the search on.”

“I would say to them, show me the tip you got. Where did this tip come from? Did it come in to your website? Did it come to someone’s phone? If so, let me look at it,” she said. “Then we’re going to go. We’re going to go backward and try to find out who sent that text or whatever.”

O’Connell said if there is no record of the tip, then you have to ask what you’re basing the search on.

For now, authorities have not verified the claims, and the search for Guthrie remains ongoing.

What happened to Nancy Guthrie?

Nancy Guthrie, 84, was reported missing from her Arizona home on Feb. 1. Authorities believe she was taken against her will.

The FBI released video more than a week later from a camera outside her front door showing a masked stranger. Her blood was found on the porch, but the case remains unsolved.

“Today” show host Savannah Guthrie says her family “cannot be at peace” while her mother’s whereabouts are unknown.

Authorities recently conducted a search near the Arizona-Mexico border, but didn’t report finding her.