Donald Trump
© Jonathan Ernst / Reuters
US President Barack Obama should be investigated because he "knew all about" Hillary Clinton's email arrangements, Republican presidential candidate Donald Trump said.

"That's why he stuck up for Hillary, because he didn't want to be dragged in. Because he knew all about her private server," Trump said in an interview with Reuters. "This means that he has to be investigated."

On Tuesday, WikiLeaks published another batch of emails from the private account of Clinton's campaign chairman, John Podesta. One of the emailed exchanges showed the campaign reacting to Obama that he learned of Clinton's private email server use from the news.

"We need to clean this up - he has emails from her - they do not say state.gov," Cheryl Mills, a longtime Clinton aide, wrote to Podesta after Obama made the comments in a March 2015 television interview.


Comment: Podesta leaks continue with 18th batch of emails from Clinton campaign chair


After losing the 2008 Democratic primary race, Clinton served as Obama's secretary of state between 2009 and 2013. During that time, she used a private email server to communicate with her aides, the State Department staff, and even the White House, as previous WikiLeaks disclosures showed.