U.S. President Donald Trump recently asked the Australian prime minister and other foreign leaders to help Attorney General William Barr with an investigation into the origins of the Russia probe that shadowed his administration for more than two years, the Justice Department said Monday.

The revelation underscores the extent to which Trump remains consumed by special counsel Robert Mueller's investigation, and the ways in which he has used the apparatus of the United States government to investigate what he believes are its politically motivated origins.

Trump's interactions with foreign leaders — and Barr's role in those discussions — are under heightened scrutiny now that the House has launched an impeachment inquiry into the president. The probe centers on Trump's summertime call with Ukraine's president, in which he presses for help investigating Democrat Joe Biden.

Read more: Trump's phone calls with Putin and other leaders are in Democrats' sights: Schiff

That call is separate from the numerous conversations Trump had with foreign leaders as part of the investigation into the Russia probe. Justice spokeswoman Kerri Kupec said Trump made those calls on Barr's behalf.

"At Attorney General Barr's request, the President has contacted other countries to ask them to introduce the Attorney General and Mr. Durham to appropriate officials," Kupec said.

Trump was requesting help for U.S. Attorney John Durham's investigation into the origins of special counsel Mueller's probe into Russian interference in the 2016 election. The investigation outraged Trump, who cast it as a politically motivated "witch hunt."