Investigators working for Robert Mueller have interviewed one of Donald Trump's closest friends and confidants, California real estate investor Tom Barrack.

U.S. President Donald Trump says it's "disgraceful" that a list of proposed questions from special counsel Robert Mueller was "leaked" to the news media.

Special counsel Robert Mueller has given a list of almost four dozen questions to lawyers for President Donald Trump as part of his investigation into Russian meddling in the 2016 election and whether Trump obstructed justice,