US PRESIDENT Donald Trump has told his Twitter followers that they are witnessing the “single greatest witch hunt in American history”.

Trump did not clarify what exactly he was referring to in yesterday’s early morning tweet, although he has frequently described reports about possible ties between members of his campaign and Russia as a “witch hunt”.

He wrote: “You are witnessing the single greatest WITCH HUNT in American political history — led by some very bad and conflicted people! #MAGA”.

Earlier, Trump tweeted that a new report suggesting that special counsel Robert Mueller may investigate him for possible obstruction of justice after he sacked FBI director James Comey is a “phony story”.

The Washington Post had reported that Mueller is seeking interviews with three Trump administration officials.