Donald Trump could still be charged with obstruction of justice when he leaves office, special counsel Robert Mueller said yesterday as he insisted the US president had not been exonerated by his report.

Mr Mueller, who for 22 months investigated Russian election meddling and alleged attempts by Mr Trump to influence his work, said he had not concluded there was “no obstruction”, as the president often claims.

The special counsel also said he did not look into whether “collusion” between the Trump campaign and Russia took place because that was not a legal term, again contradicting the president who claims “no collusion” was found.

Mr Mueller, a 74-year-old former FBI director, gave the remarks during the first and likely only time he will answer questions from congressmen about his 448-page report on Russian interference in the 2016 US election.

Mr Mueller explained that he had been bound by Department of Justice guidelines that say a sitting president cannot be indicted when determining whether around a dozen episodes involving Mr Trump amounted to obstruction of justice.

Those incidents included Mr Trump ordering a legal aide to fire the special counsel, demanding his attorney general take back control over the Russia investigation and critical public tweets about the probe he issued.