A Reddit user who has a history of racist and anti-Muslim posts is taking credit for the anti-CNN video that Donald Trump tweeted on Sunday.

The president was accused of encouraging "violence against reporters" after he shared a mocked-up video of him beating up a man with the broadcaster's logo over his face.

The 28-second clip, which was shared on both his personal and presidential Twitter accounts, shows Mr Trump tackling a man to the floor and pummelling him in a video taken from pro-wrestling event Wrestlemania XXIII.

The video was posted several days ago by a user on the social media site Reddit with the title, "Trump takes down fake news."