A government watchdog group on Friday urged the Justice Department's inspector general to investigate whether acting Attorney General Matthew Whitaker violated federal ethics standards when he decided not to recuse himself from involvement in special counsel Robert Mueller Robert (Bob) MuellerCNN's Toobin warns McCabe is in 'perilous condition' with emboldened Trump CNN anchor rips Trump over Stone while evoking Clinton-Lynch tarmac meeting The Hill's 12:30 Report: New Hampshire fallout MORE's Russia probe.

In a letter to Inspector General Michael Horowitz, Citizens for Responsibility and Ethics in Washington (CREW) noted that Justice Department ethics officials had questioned Whitaker's impartiality concerning Mueller's investigation, but that Whitaker had neglected to recuse himself as agency ethics rules would dictate.

ADVERTISEMENT

"Department of Justice ('DOJ') ethics officials determined that a reasonable person would likely question Acting Attorney General Whitaker’s impartiality if he participated in Special Counsel Mueller’s investigation and concluded he should recuse from supervising it," CREW Executive Director Noah Bookbinder wrote in the letter.

"Making this independent determination triggered a mandatory requirement that Acting Attorney General Whitaker recuse from the investigation. By refusing to do so, Acting Attorney General Whitaker violated the Standards of Conduct," Bookbinder added.

Whitaker's views on the Mueller investigation resurfaced last month following his appointment to serve as acting attorney general following the departure of Jeff Sessions Jefferson (Jeff) Beauregard SessionsGOP set to release controversial Biden report Trump's policies on refugees are as simple as ABCs Ocasio-Cortez, Velázquez call for convention to decide Puerto Rico status MORE. In opinion pieces for The Hill and CNN he wrote about the possibility of defunding the special counsel probe.

Democratic lawmakers have raised concerns about Whitaker's appointment based on his past statements about the Mueller probe.

CNN and The Washington Post reported this week that Justice Department ethics officials had urged Whitaker to recuse himself, for the sake of appearances, despite earlier news reports indicating otherwise.

Trump has nominated William Barr to succeed Sessions as attorney general.

If confirmed by the Senate, Barr would replace Whitaker as the top official overseeing the Mueller investigation, which is currently in its second year of operation.