• Supreme Court Justice Clarence Thomas has accepted secret luxury trips from Republican megadonor Harlan Crow for more than two decades, ProPublica reported.
• The trips appear to violate a law requiring disclosure for private jet flights.
• Thomas has come under fire from ethics experts and other critics over his wife Ginni Thomas' political activities.

Supreme Court Justice Clarence Thomas has accepted secret luxury trips from Republican megadonor Harlan Crow for more than two decades in apparent violation of a financial disclosure law, a ProPublica report revealed Thursday.

Thomas has vacationed on Crow's 162-foot superyacht, flown on the real estate developer's private jet and spent time at the GOP donor's private resort and other exclusive retreats, ProPublica reported, citing documents and dozens of interviews.

Thomas, the 74-year-old conservative associate justice who has served on the nation's highest court since 1991, has not reported the trips on his financial disclosures as required by law, the nonprofit newsroom reported.

The investigation offers more fuel for Thomas' critics, who say his refusal to recuse himself from cases touching on issues related to his wife's political work in conservative circles — including her involvement in schemes to overturn the 2020 election — poses a conflict of interest.

Ethics experts and ex-judges interviewed by ProPublica were incredulous. Thomas "seems to have completely disregarded his higher ethical obligations," Virginia Canter, chief ethics counsel at the watchdog group CREW, told the outlet.

"When a justice's lifestyle is being subsidized by the rich and famous, it absolutely corrodes public trust," Canter said.

Spokespeople for the Supreme Court and Crow did not immediately respond to CNBC's request for comment on the investigation.

In a statement to ProPublica, Crow said, "The hospitality we have extended to the Thomas's over the years is no different from the hospitality we have extended to our many other dear friends."

Thomas and his wife, Ginni Thomas, "never asked" for any of the gifts, nor for any of the contributions the Crows have made to projects celebrating the justice's "life and legacy," the megadonor said. Crow added that he and his wife "have never asked about a pending or lower court case, and Justice Thomas has never discussed one, and we have never sought to influence Justice Thomas on any legal or political issue."

Crow, a Texas real estate magnate, became friends with Thomas after he joined the Supreme Court. He has given more than $10 million in publicly disclosed political donations, and unknown amounts to groups that aren't required to reveal their donors, ProPublica reported.

Thomas typically spends about a week each summer at Topridge, Crow's private lakeside resort in the Adirondacks, and flight records show he has used Crow's plane numerous times, according to the news outlet.

In 2019, shortly after the court shared its final opinion of the term, Clarence and Ginni Thomas took off on Crow's private jet for a nine-day vacation in Indonesia aboard the donor's yacht — a trip that cost more than $500,000, according to ProPublica.

The report also cited records showing that Thomas had been at Topridge at the same time as major GOP donors, corporate executives and a leader of the conservative American Enterprise Institute during a July 2017 trip.

A painting hanging inside the lakeside resort shows Thomas and Crow smoking cigars and chatting with conservative figures, the report said. They include Leonard Leo, the influential Federalist Society leader credited with helping former President Donald Trump pick his judicial nominations and shift federal courts to the right.

Crow contended in his statement that he was "unaware of any of our friends ever lobbying or seeking to influence Justice Thomas on any case."

Supreme Court justices are constrained by fewer ethical restrictions than lower rungs of the judiciary. Some groups have called to implement a code of ethics for the high court.

But justices still submit financial disclosures, and experts say they are required to disclose all gifts valued at more than $415. While there are exceptions to that requirement, transportation is not one of them.

"If Justice Thomas received free travel on private planes and yachts, failure to report the gifts is a violation of the disclosure law," Kedric Payne, senior ethics director for the Campaign Legal Center, told the outlet.

Senate Judiciary Committee Chairman Dick Durbin, D-Ill., later Thursday morning called for an "enforceable code of conduct" for Supreme Court justices as he slammed Thomas over the reported secret trips.

"The highest court in the land shouldn't have the lowest ethical standards," Durbin said in response to the report. "This behavior is simply inconsistent with the ethical standards the American people expect of any public servant, let alone a Justice on the Supreme Court."

Read the full report from ProPublica.