Savannah Guthrie shared a rare family photo to mark Father's Day on Sunday, as federal authorities review a possible blunder made by cops in the early days of the probe into her mother's disappearance.

The Today Show host, 54, posted a photo of her husband, Michael Feldman, lying in bed and cuddling with their two children - daughter Vale, 11, and Charley, nine - on Instagram.

'Our hero,' she called the business consultant, whom she married in March 2014.

The couple first met at Feldman's 40th birthday party in 2008 and began dating the following year.

After getting engaged in 2013 and marrying the following year, Guthrie and Feldman have largely kept their relationship out of the spotlight.

But Guthrie's family took on new public interest earlier this year, when her 84-year-old mother, Nancy, was abducted from her $1 million home in Tucson's affluent Catalina Foothills neighborhood.

Nearly six months have since passed without any answers as to what happened to the mother-of-three in the early morning hours of February 1.

Without any new leads, federal investigators are now said to be re-examining their decision to pay just a small amount of ransom money in the early days of the investigation.

TMZ had announced it received a ransom note just three days after Nancy went missing, demanding the Guthrie family fork over $4 million in Bitcoin for her return.

It said she was 'safe but scared,' and included details that had not yet been released to the public such as the floodlight in Nancy's backyard and what she was wearing at the time of her abduction.

The note concluded with a deadline for the ransom to be paid 'or else'.

Yet the task force investigating the 84-year-old's disappearance decided instead they would 'tickle the wire' by depositing just $152 into the specified cryptocurrency address, Air Mail reports.

The hope was that authorities would be able to trace the money once the abductor transferred the funds out of the account and tried to cash it.

But the plan hit a snag when the Bitcoin remained untouched in the cryptocurrency wallet, possibly because the family did not pay the requisite ransom or the abductor suspected a trap when the nominal amount came through.

When the deadline then passed days later, another ransom email was sent from the same IP address.

It opened with a longwinded 'apology' for Nancy's inadvertent death and offered the family the possibility that her body be returned to them for a sum, a source familiar with the investigation told Air Mail.

The following day, Savannah posted a heartbreaking clip on Instagram, sitting next to her brother, Camron, and sister, Annie. 

'We beg you now to return our mother to us, so that we can celebrate with her,' the Today Show host pleaded in the video posted to her Instagram page.

'This is the only way we will have peace. This is very valuable to us, and we will pay.'

Savannah has since said she believes those ransom notes were real. 

As the investigation into Nancy's disappearance now continues, federal authorities are also re-examining the letters for any clues about the captor's identity, according to Air Mail.

They note that the ransom letters show that the captor is articulate and knowledgeable about the intricacies of cryptocurrency.

The fact that he apologized also suggests the kidnapper is not a coldhearted cartel member as they had originally feared, but was rather a local opportunist who was in over his head.

Authorities are also probing the possibility the abductor may have had an accomplice - a masked man who was seen trying to remove Nancy's Nest doorbell camera on the night of her disappearance, according to Air Mail.

Federal investigators say the masked man's bumbling attempt to remove or cover up the doorbell camera does not seem to align with their profile of the articulate and cunning suspect, the outlet reports.

No suspects have been publicly identified in the case.

According to reports from Page Six, investigators have uncovered only limited physical evidence, including a single strand of hair and a glove found near Nancy's home. 

The DNA evidence recovered near the scene has since undergone extensive testing at an FBI crime lab after initially being processed by a private laboratory in Florida.

But Pima County Sheriff Chris Nanos said 'the testing moves at a snail's pace.'

He noted in an interview with People that local authorities have already combed through 'thousands and thousands' of hours of video footage gathered from traffic intersections and Ring doorbell cameras across the Tucson area. 

'There's way too much work to be done, that is ongoing, with some of the physical evidence we have,' Nanos said last month. 'And we're not going to give up on it just because it's been 100 days.'

The sheriff added: 'When you have the best minds of the country working on problems, I think they're gonna solve them. It just takes time.'

In an earlier interview with KOLD, the sheriff also revealed investigators possess information they are deliberately withholding.

'It's not done because we got to keep it secret,' Nanos explained. 'It's done because we got to protect our case.'

The sheriff then maintained that he remains convinced detectives will eventually identify the masked suspect seen on surveillance footage tampering with Nancy's doorbell camera.

'I believe at some point in time, we will make an arrest in this case,' he said. 'And whoever that individual is, that individual will have a right to a fair and impartial trial.'