GOP megadonor Harlan Crow isn't charging Clarence Thomas' mother rent. Zillow estimates suggest that would have saved her $155,000 since 2014.

• GOP megadonor Harlan Crow bought SCOTUS justice Clarence Thomas' mother's house in October 2014.
• Thomas' mother still lives there rent-free, CNN reported. According to Zillow estimates, that would have saved nearly $155,000.

Clarence Thomas' mother is living rent-free in the home GOP megadonor Harlan Crow bought from the family, according to CNN.

And that deal may have saved her more than $150,000 in rent for the property, according to Zillow estimates.

Last week, ProPublica revealed Crow's undisclosed 2014 purchase of Supreme Court Justice Clarence Thomas' childhood home in Savannah, Georgia — part of a widening scandal around Thomas and Crow's close relationship.

An occupancy agreement allows Thomas' 94-year-old mother, Leola Williams, to stay in the home without paying rent for the rest of her life, CNN reported. While Williams doesn't pay rent, she's responsible for other expenses such as property taxes and insurance, CNN added.

According to Zillow's estimates for what the property would cost to rent, Williams could have saved as much as $154,900 over the years.

Zillow estimates suggest that the Savannah property's rent has fluctuated between $1,100 and $2,400 over since its sale on October 15, 2014.

ProPublica reported that after the sale, renovations equating to thousands of dollars were made to the home, including a repaired roof and a new carport. Slate reported that Williams still lives at the home.

The news comes just days after another ProPublica report on Thomas' relationship with Crow, which included over 20 years of luxury vacations and gifts that Thomas accepted and never disclosed.

Thomas defended the trips by citing a "personal hospitality" exemption in disclosure requirements.

Over the past few weeks, Thomas has faced growing calls to resign or be impeached. But legal experts told Insider that there's basically no chance the conservative justice will be removed thanks to a lack of regulatory and disciplinary options for dealing with corruption on the Supreme Court.

Crow lashed out at ProPublica and the broader narrative of his relationship with Thomas in an extensive interview with The Dallas Morning News. The billionaire said it was "insane" to suggest that he would ever try to influence the current longest-serving justice.

As for the properties he purchased, Crow said "kind of drives me crazy" that anyone would think there was anything untoward about the transactions. The Dallas developer said he wants to eventually build a museum centered on Thomas' boyhood home at the site.

"His life story is an amazing American life story: born into deep poverty. Father gone. Mother — the lady whom we're talking about — really not able to do a lot to help raise her two sons," Crow said. "Ultimately raised by his grandparents, who were illiterate. Growing up in Jim Crow Georgia."

As for additions to the home, Crow tried to cast any improvements as modest upgrades for an old woman.

"When we made this purchase, she was just an 84-year-old lady, or something like that. I built a carport, so that she can park her car. It's not an enclosed garage. That's what I did," Crow said. "Now, you said improvements to the house. I don't remember any other rooms. However, if there was a commode that was terrible, I might have fixed it. I don't know."