Further details about the relationship between a global real estate magnate and a Supreme Court justice will remain unclear for now.

Harlan Crow, former CEO and current chairman of the board at Crow Holdings, won't comply with requests from the Senate Finance Committee to answer members' questions about trips and gifts for Supreme Court Justice Clarence Thomas that Crow paid for over the years, CNN reported.

"We have serious concerns about the scope of and authority for this inquiry,” Michael D. Bopp, a lawyer for Crow, said in a letter to committee Chairman Ron Wyden that CNN obtained.

Bopp described the questions as "a component of a broader campaign against Justice Thomas and, now, Mr. Crow, rather than an investigation that furthers a valid legislative purpose," CNN reported.

Crow Holdings didn't immediately respond to a request for comment.

Last month, ProPublica reported that Thomas received millions of dollars worth of gifts — yacht trips, flights on private jets, private school tuition for a member of Thomas' family — over more than 20 years without disclosing them. Crow also made a $500K donation to a Tea Party-affiliated group from which Thomas' wife, Ginni Thomas, received a $120K salary.

The pair also had real estate dealings together, with Crow buying properties owned by Thomas and members of his family, reportedly to start a museum dedicated to Thomas' life.

In April, Thomas released a statement framing the vacations as part of his and his wife's 25-year friendship with Crow.

"As friends do, we have joined them on a number of family trips during the more than quarter century we have known them," the statement said.