India, June 2 -- Savannah Guthrie has spent $500,000 on private investigators to try to solve the case of her mother Nancy Guthrie's disappearance, the US Sun reported.

"She is not prepared to stop looking for her mother. She feels that depending only on the official investigation is not enough anymore - that's why she's investing so heavily in private investigators and outside specialists," a source told the outlet.

NewsNation senior national correspondent Brian Entin said that he could not confirm the report, and mentioned on 'Jesse Weber Live' in Las Vegas, where he hosted a weekend panel at CrimeCon about the case, that he hasn't "heard anything about any private investigators."

"At the same time, I would imagine that Savannah Guth...