Justice Clarence Thomas is raising eyebrows over a new report that claims he has accepted luxury trips from a Republican megadonor without disclosing them.

Experts say his failure to report the flights appears to violate a law passed after Watergate that requires justices, judges, members of Congress, and federal officials to disclose most gifts, even private jets.

Brian Fallon, the executive director of Demand Justice called for the Senate to not let “this extraordinary display of corruption and lawbreaking go unanswered.”

“Senate Democrats cannot force Thomas to resign or give him the impeachment trial he clearly deserves, but they can hold hearings to further expose Justice Thomas’ apparent lawbreaking and the Republican justices’ deep ties to far-right donors,” Fallon continued.

The trips reportedly appeared nowhere on Thomas’ financial disclosures. The extent and frequency of Crow’s apparent gifts to Thomas have no known precedent in the modern history of the U.S. Supreme Court.