TUCSON, Ariz. – The Pima County Sheriff's Department confirmed on Tuesday it is "aware" of reports of a possible ransom note in relation to the disappearance of Nancy Guthrie, mother of NBC "Today" co-host Savannah Guthrie.

"We are aware of reports circulating about possible ransom note(s) regarding the investigation into Nancy Guthrie," officials wrote in a statement Tuesday afternoon. 

The sheriff's office added it is taking all tips and leads "very seriously."

"Anything that comes in, goes directly to our detectives who are coordinating with the FBI," officials wrote.

The announcement came minutes after ransom note demanding a "substantial amount" of money in the form of Bitcoin cryptocurrency for Guthrie's return.

TMZ said it verified the Bitcoin address is "real," noting it included unreleased details about her disappearance.

TMZ said it contacted law enforcement, as the note included a deadline.

Local outlet KOLD 13 News also reportedly received what appears to be a ransom note, though it is unclear if the letters received by TMZ and KOLD are identical.

"Our newsroom also received what appears to be a ransom note, and we have sent it to law enforcement," KOLD reporter Mary Coleman wrote in her Tucson home at about 9:30 p.m. Saturday, according to the sheriff's office. 

While officials did not immediately elaborate on the circumstances of her disappearance, they said they believe Guthrie was either kidnapped or abducted.

A law enforcement source told Fox News Digital that there were "blood drops" leading from the entryway outside down the house's pathway toward the driveway. 

Guthrie did not attend her Sunday church service, leading another churchgoer to notify the family, Pima County Sheriff Chris Nanos said.

Family members went to the house at about 11 a.m. and called 911 around noon.

The Pima County Sheriff's Department told Fox News Digital on Monday that officials believe Nancy Guthrie was either kidnapped or abducted.

It is unclear if she was targeted, or if the suspected kidnapping was random.

Savannah Guthrie spoke out on Instagram in a post Monday, writing "We need you."

"We believe in prayer. We believe in voices raised in unison, in love, in hope. We believe in goodness. We believe in humanity. Above all, we believe in Him," she wrote. "Thank you for lifting your prayers with ours for our beloved mom, our dearest Nancy, a woman of deep conviction, a good and faithful servant. Raise your prayers with us and believe with us that she will be lifted by them in this very moment."

Anyone with information on the disappearance of Nancy Guthrie is asked to call the tipline at 1-800-CALL-FBI.

This is a developing story. Please check back for updates.