The FBI is investigating extortion demands related to Nancy Guthrie’s disappearance that “may potentially be legitimate”, the agency said on Wednesday.

The update comes a day after Reuters reported that kidnapping notes received in Guthrie’s case were fake.

After the disappearance of the Today show co-host Savannah Guthrie’s mother in February, several media outlets received three messages regarding the case. Two of the messages were ransom notes, while the third was a message from someone who claimed they knew the identities of the perpetrators, the outlet reported.

Federal investigators assessing the communications found that they were fake, according to an unnamed FBI official who spoke to Reuters.

“None of the ransom ​notes are believed to be genuine,” the official said.

The FBI clarified on Wednesday that while some ransom notes have been deemed “extortion attempts without legitimacy”, others remain under investigation.

“The FBI and its task force partners have received several ransom notes over the course of this investigation,” read the statement posted to social media. “Some have been deemed to be extortion attempts without legitimacy. Other ransom demands may potentially be legitimate and are still being investigated as such. This case continues to be investigated as a kidnapping for ransom case.”

Nancy Guthrie disappeared from her Arizona home in early February, and police found blood near her front door and believe she was abducted from her home. Surveillance videos released by the FBI showed a masked man on her porch the night Guthrie disappeared.

Law enforcement launched a massive search for the 84-year-old, with teams scouring the nearby desert.

In the first note received by media outlets, the author reportedly demanded a ransom in the millions in the form of cryptocurrency. The FBI deposited a small sum in the account included in the note as part of an effort to confirm the authenticity of the communication and track down the perpetrators, Reuters reported, but the money was left in the account.

The source told the outlet that it ultimately concluded the notes were “of a common origin were nevertheless sent by a person or persons not actually connected with Guthrie’s disappearance”, Reuters reported. Investigators also determined a third note, which media outlets reported on last week, was fake.

Savannah Guthrie has continued to bring attention to her mother’s case and plead for answers. “We love our mom,” she said last week. “And we will never stop looking for her.”