US Supreme Court Justice Clarence Thomas has acknowledged he took three trips aboard a Republican megadonor’s private plane last year, as an ethics row grips the nation’s top court.
The conservative judge said failing to previously report receiving such hospitality had been “inadvertent”.
Supreme Court judges are required to file annual financial disclosure forms.
Justice Thomas was among the last to do so, but he is not the only one facing potential conflicts of interest.
Critics are pushing to adopt a new ethics code for the nine justices who receive lifetime appointments to the nation’s highest court.
It follows a series of US media reports that revealed Justice Thomas, 75, had failed to disclose several expensive gifts from Harlan Crow, a wealthy real estate developer and conservative benefactor.
ProPublica, an investigative journalism non-profit, reported Mr Crow paid for private school tuition for a child raised by the judge, purchased the Georgia home where the judge’s mother resides, and has lavished him with luxury trips for more than two decades.
Under the rules for sitting members of the US federal judiciary, a Supreme Court justice should list the “personal hospitality of any individual” as a gift.
But, prior to the disclosure report released on Thursday, Justice Thomas had never reported such gifts, raising questions whether Mr Crow may have leveraged their friendship to influence business before the court.
The justice has defended his actions in the past, stressing that the Crows count “among our dearest friends” and had never appeared before him in court.
His attorney alleged in a statement that the ethics complaints stem from “left wing “watchdog” groups” who are “motivated by hatred for his judicial philosophy”.
“After reviewing Justice Thomas’s records, I am confident there has been no wilful ethics transgression, and any prior reporting errors were strictly inadvertent,” Elliot S Berke said.
“The attacks on Justice Thomas are nothing less than ridiculous and dangerous, and they set a terrible precedent for political blood sport through federal ethics filings.”