Trump under investigation but not criminal target: report

US President Donald Trump is under investigation by special counsel Robert Mueller but is not currently considered a criminal target, The Washington Post reported Tuesday.

Mueller is investigating possible collusion between Russia and Trump's campaign, a probe the president has denounced as a "witch hunt."

The newspaper, quoting three anonymous sources, said that Mueller considers Trump a subject of the investigation, meaning there is currently not enough evidence to bring criminal charges.

Additionally, Mueller told the president's lawyers that he is preparing a report on Trump's actions and possible obstruction of justice, the Post said.

Mueller, a former FBI director and federal prosecutor, was named last May to investigate possible collusion between the Trump campaign and Russia.

US intelligence agencies say Russian President Vladimir Putin himself was behind a hacking and disinformation effort to disrupt the election and boost Trump's chances of winning.