In a second tweet a few minutes later, the president once again called the Russian Federation investigation a "witch hunt" and called the people leading it "very bad", apparently a reference to Mueller and others at the FBI.
The Washington Post reported late Wednesday that special counsel Robert Mueller is seeking interviews with three Trump administration officials who weren't involved in Trump's campaign.More news: White House, Pentagon to take regionwide approach in new Afghan war plan
He also brought up Hillary Clinton's use of a private email server and questioned whether her actions amounted to obstruction of justice. The obstruction investigation began just days after the president abruptly fired former FBI Director James Comey, according to the newspaper.
Comey told the Senate hearing that he believed he was dismissed by Trump because he did not stop the FBI's investigation into Flynn.
Together, the requests from Mueller suggest new scrutiny on whether the president tried to influence the Russian Federation investigation through conversations he had with Comey, whom he ultimately fired, or with other officials.More news: President says Sessions did 'very good job,' comments on Mueller rumors
Starr also argued on Thursday that Attorney General Jeff Sessions was "on very solid constitutional ground" when he said he had to protect the "president's privilege" when it comes to revealing conversations publicly.
The reports, released past year, say Clinton destroyed her used phones on at least two occasions while serving as secretary of state, also that she used the "BleachBit' software to delete some of her mails".
The probe into Trump was sparked in part by the sudden dismissal of FBI Director James Comey.More news: Number of Britons granted German citizenship quadruples