The federal courts' policy-making body is defending its decision in 2011 to not refer Justice Clarence Thomas to the Justice Department to investigate allegations that his pattern of nondisclosure on his financial reports broke federal law.

In 2011, the Judicial Conference received a number of complaints from lawmakers and watchdog groups about Thomas after media reports revealed that he failed to disclose income his wife earned between 1998 and 2003 from The Heritage Foundation, a conservative think tank.

The complaints asked the conference to refer the matter to the US attorney general to probe whether the justice's behavior ran afoul of a federal ethics law.

But Thomas quickly amended his reports when the allegations were brought to his attention, and so it was decided no further action was needed, Roslynn Mauskopf, the conference's secretary, wrote in a letter Monday to Democratic Sen. Sheldon Whitehouse, who chairs a Senate Judiciary subcommittee looking into court ethics.

"The then-chair of the committee, the Honorable Bobby R. Baldock, reviewed the January 2011 allegations and the amended reports and concluded that the reports were properly amended and that no further action was warranted," Mauskopf wrote.

The decades-old complaints have reentered the spotlight amid recent reports about Thomas' decision to not disclose years of luxury travel and expensive gifts that were paid for by GOP megadonor Harlan Crow, as well as a real estate deal he and his family cut with the donor.

Those reports have fueled similar calls by lawmakers and watchdog groups for the Judicial Conference to refer the justice to the attorney general for potential violations of the ethics law, and CNN has reported that Thomas intends to amend his financial disclosure forms to reflect the 2014 real estate deal.

On Wednesday, a sitting federal judge who raised concerns about how the conference handled the 2011 complaints against Thomas will testify before a Senate panel.

US District Judge Mark Wolf, an appointee of President Ronald Reagan, will appear before Whitehouse's subcommittee, where he'll likely face questions from lawmakers about his concerns at the time.

When the complaints were made in 2011, Wolf was serving on the conference, which is comprised of a small selection of federal judges from various courts from around the country.