An investigation is under way into whether President Donald Trump lied in his testimony to Special Counsel Robert Mueller.
According to CNN, the US House of Representatives is looking at the written evidence given by the president to the inquiry about Russian interference in the the 2016 election.
The House's general counsel told a federal court in Washington on Monday that lawmakers are examining whether Mr Trump's written answers to federal investigators were untruthful, CNN reported.
It comes as the US president is also facing impeachment proceedings.
A spokeswoman for the House Judiciary Committee could not be immediately reached for comment.
According to CNN, House general counsel Douglas Letter told the US Court of Appeals for the District of Columbia Circuit: "Did the President lie? Was the President not truthful in his responses to the Mueller investigation?"
Mr Mueller submitted a report to US Attorney General William Barr in March after completing a 22-month investigation that detailed Russia's campaign of hacking and propaganda to boost Mr Trump's candidacy in the 2016 election as well as extensive contacts between the Trump campaign and Moscow.
Last week, Mr Trump's former deputy campaign chairman Rick Gates testified that the 2016 Trump presidential campaign was keen to keep abreast of the release of emails potentially damaging to Democratic candidate Hillary Clinton.
That appeared to conflict with sworn written statements that Mr Trump gave Mr Mueller.
