US President Donald Trump's eldest son asked a House of Representatives committee on Tuesday to investigate possible leaks of information about his December 6 interview with lawmakers, as congressional probes of Russia and the 2016 election picked up steam ahead of the New Year.
Alan Futerfas, an attorney for Donald Trump Jr, asked Representative Michael Conaway, the Republican leading the House Intelligence Committee's investigation of alleged Russian meddling in the election, to look into comments he said came from committee members and staff that were included in media reports.
"To maintain the credibility of the Investigation, this Committee should determine whether any member or staff member violated the Rules," he said in a letter to Conaway.
Separately, the Associated Press reported that Trump Jr was due to appear in Congress again on Wednesday, this time before the Senate Intelligence Committee, citing a source familiar with the matter.
The Senate and House Intelligence panels are conducting the main congressional investigations after US intelligence agencies found that Moscow attempted to influence the campaign to help the Republican Trump defeat his Democratic opponent, Hillary Clinton.
They are also working to determine whether Trump associates colluded with Russia.
Moscow denies seeking to influence the election, and Trump has dismissed any talk of collusion.
The two committees, sometimes members and sometimes staff, have been conducting frequent interviews with a variety of witnesses, seeking to wrap up their investigations well before the US congressional elections in November 2018.
Burr said he felt "some urgency" related to election security related to next year's vote. He said he expected the Senate committee's investigation would last into 2018, and that there were dozens more people still to be interviewed.
"So it's going to carry over (into next year), but it's not going to carry over far unless the basket of people (to be interviewed) changes, and the only way that changes is if we learn of individuals that we didn't know about today," Burr told reporters at the US Capitol.
He said the committee did not now plan any more public hearings in its Russia probe.
Separately, Sam Clovis, a former Trump campaign official, was interviewed by the House Intelligence Committee for more than four hours on Tuesday. He came to the attention of investigators after a report that he encouraged George Papadopoulos, a one-time Trump foreign policy campaign adviser, to improve relations between the United States and Russia.
Clovis' attorney denied those reports. She did not respond immediately to a request for comment about his House testimony on Tuesday.