A new report on Thursday alleged even deeper financial ties between Supreme Court Justice Clarence Thomas and billionaire Republican donor Harlan Crow.
According to ProPublica, Crow paid for private school tuition for Thomas' grandnephew Mark Martin, whom Thomas said he was raising as a son.
The publication said Crow paid $6,200 monthly tuition for Martin's attendance at Hidden Lake Academy in 2009, citing a bank statement and an interview with a former administrator at the school. That former administrator told ProPublica Crow told him he also paid for Martin's tuition at Randolph-Macon Academy, which he attended before Hidden Lake Academy.
The total amount paid by Crow is unclear but could have exceeded $150,000, the outlet reported. Thomas didn't report the payments on his financial disclosure filings, though he did disclose another $5,000 gift for Martin's education from another individual in 2002.
Crow's office said in a statement provided to ABC News Crow "has long been passionate about the importance of quality education and giving back to those less fortunate, especially at-risk youth" and that he and his wife have supported many young Americans through schooling.
"These scholarships and other contributions have always been paid solely from personal funds, sometimes held at and paid through the family business," the office said. "It's disappointing that those with partisan political interests would try to turn helping at-risk youth with tuition assistance into something nefarious or political."
Neither the Supreme Court nor Justice Thomas has commented to ABC News on the new ProPublica report.
Senate Finance Committee Chairman Ron Wyden, D-Ore., in light of the ProPublica report, reupped his request that Crow make a full accounting of his hospitality to Thomas -- and threatened action if he failed to comply.
"With every new revelation in this case, it becomes clearer that Harlan Crow has been subsidizing an extravagant lifestyle that Justice Thomas and his family could not otherwise afford," Wyden said in a statement. "This is a foul breach of ethics standards, which are already far too low when it comes to the Supreme Court. I gave Mr. Crow until May 8th to provide a full account of the gifts he provided to Justice Thomas's family. Should he fail to comply, I will explore using other tools at the committee's disposal to obtain this critical information."
Thomas has been under scrutiny since ProPublica's first report last month showing he and his wife were treated to luxury private travel and accommodation from Crow and did not disclose them on his annual financial disclosure filings.
Thomas, in response to that report, said it was his understanding that he wasn't not required to report "this sort of personal hospitality from close personal friends."
The revelations have prompted Democrats to push for greater oversight of the Supreme Court and calls for justices to adopt a formal code of conduct. The high court is the only federal branch that is not subject to an enforceable ethics code.
"I hope that Chief Justice Roberts reads this story this morning and understands something has to be done," Senate Judiciary Chairman Dick Durbin, D-Ill., said on Thursday. "The reputation of the Supreme Court is at stake here, the credibility of the court when it comes to its future decisions is at stake, and his reputation as the leader of this court is really at issue as well."
But any legislative effort to force the court to adopt a code will face steep Republican opposition. GOP lawmakers, during a Senate Judiciary Committee hearing this week, came to Thomas' defense and accused Democrats of "selective outrage" as they listed other justices who previously received all-expense-paid trips and monetary awards.
"He's obviously been targeted, because he is a conservative black man and he is on the Supreme Court, in an effort to undercut the legitimacy of the court," Sen. John Cornyn, R-Texas, said on Thursday. "I think the best thing for Chief Justice Roberts and the judges to do is to take this experience an go back and consider whether there are changes in their code of ethics for the Supreme Court are appropriate."
Ethics for the court are "not for Congress to dictate," Cornyn said.
The justices, too, have rebutted proposals for independent oversight and mandatory compliance with ethics rules.
In a joint statement, all nine justices pledged their voluntary adherence to a general code of conduct and "consult a wide variety of authorities to address specific ethical issues."
"This statement aims to provide new clarity to the bar and to the public on how justices address certain recurring issues," they wrote, "and also seeks to dispel some common misconceptions."
-ABC News' Allison Pecorin and Trish Turner contributed to this report.