Investigators were seen searching the home of Annie Guthrie, who is the sister of Savannah Guthrie, the host of the talk show “Today,” as authorities continue to search for the disappearance of their mother, Nancy Guthrie.

“At Annie Guthrie’s home see what appears to be unmarked police vehicles at the scene,” Fox News Digital’s Sarah Rumpf-Whitten wrote late Saturday in sharing a video of the activity. “White flashes are visible coming from the garage, which appears to be investigators taking photographs.”

Nancy Guthrie, 84, is missing. She is the mother of “Today” show host Savannah Guthrie. The search for her has now gone on for a second, painful week, putting more pressure on investigators and leaving her family dealing with uncertainty.

Guthrie hasn’t been seen since January 31, when she disappeared from her remote home in Arizona’s Catalina Foothills without her phone or important medicines. She was reportedly kidnapped. The final ransom deadline was allegedly at 5 pm on Monday.

While she has been missing for a long time, things have taken some scary turns: there have been rumors of ransom notes demanding millions of dollars, a full-on investigation, and heartbreaking videos of Guthrie’s children pleading for her return.

A former NYPD inspector astonished Fox News hosts this weekend with a somber theory regarding the silence of Nancy Guthrie’s suspected kidnappers in ransom discussions: they are unable to provide proof of life.

“Well, you’re elusive on the communications because you know you’re going to be asked for proof of life that you can’t provide,” retired NYPD Inspector Paul Mauro said on Fox News’s “The Big Weekend Show.”

The comment hit co-hosts Joey Jones and Tomi Lahren hard.

“Emmmm,” Jones groaned off camera. Lahren audibly sighed after hearing the prediction.

“I feel like they’ve been playing games with the details in the house and all of that,” Mauro said. “They probably planned for the idea that they could provide proof of life, and now they find themselves in a spot where, ‘We can’t. And so what do we do? Now we gotta bargain for something else. We gotta bargain to give back something else.’”

“That’s my read with the limited facts we have, hoping against hope I’m wrong,” Mauro said, but he also warned that the entire situation could “all be a hoax.”

“Would you say… that they didn’t mean to hurt her, but something might have gone wrong, and now they’re still trying to get their payday out of this. Is that what I heard you kind of allude to?” Lahren asked.

Mauro said that one problem could be that Nancy Guthrie needs certain medications, and the kidnappers may not have been able to get them without drawing attention.

Federal agents searched a septic tank at Nancy Guthrie’s Tucson home on Sunday, just hours before a reported $6 million ransom deadline set for Monday night. People saw deputies using a long pole to poke around in the tank and shining flashlights inside.

The authors of the ransom note in the Nancy Guthrie case may have inadvertently revealed that they were operating outside the United States because of one small detail in their message: they specified that the multi-million-dollar demands be paid in US dollars, according to law enforcement experts.

“Why would you use that if you’re a domestic person? That points to somebody who might be potentially outside the country, which also lends the potential for this being a scam,” former FBI agent Michael Harrigan told the New York Post.

“If you’re domestic, why would you ever put ‘USD?’ You put six million,” he added.

Guthrie’s alleged kidnappers demanded a ransom to be paid in Bitcoin, but specified that the payment should be in USD. They set two deadlines: the first at 5 p.m. MT on Thursday, with the amount increasing if the payment was not made by this deadline and was instead submitted by a Monday deadline.

Since the note was first sent to news outlets last week, the sender has not contacted law enforcement or the Guthrie family. Investigators are still trying to determine whether the notes are genuine.

There are still no suspects or person of interest — and no suspect vehicles have been identified, The Post noted further.