WASHINGTON, July 24 (Xinhua) -- Former special counsel Robert Mueller on Wednesday morning arrived on Capitol Hill for highly-anticipated hearings before two congressional panels about his probe into alleged Russian interference in the 2016 U.S. presidential election and possible obstruction by U.S. President Donald Trump.

After testifying before the House Judiciary Committee in the morning, Mueller will appear before the Intelligence Committee later in the afternoon. The two hearings are expected to last roughly five hours combined.

The wide-ranging inquiry, which had haunted the White House for nearly two years, concluded in March this year, when Mueller submitted a 448-page report to Attorney General William Barr.

A public version of the report stated that there was no evidence that Trump's campaign conspired with the Russian government during the 2016 U.S. presidential election but didn't conclude if the president had obstructed justice.

Instead, Mueller recounted 10 episodes involving Trump and discussed potential legal theories for connecting these actions to elements of an obstruction offense.

It was the Department of Justice that concluded that Mueller did not have "sufficient" evidence to support a charge in the obstruction case, a decision that has drawn scrutiny from Democrats, who have called for more investigations and Mueller's congressional appearance.

Mueller indicated that he did not want to testify before Congress during a press conference in May, adding that his testimony would not go beyond his report. Nevertheless, his words failed to discourage Democrats from subpoenaing him to testify.