Far-right conspiracy theorist Alex Jones has said that Donald Trump is being "covertly drugged" with small amounts of sedative in his drinks.

In a video posted to his website Infowars.com, the radio presenter said the US president had been fed tranquilisers for around two months and they were making his speech slur.

Mr Jones cited sources close to the President, but he did not provide any evidence for the claim.

“It's known that most presidents end up getting drugged," he said. "Small dosages of sedatives till they build it up. Trump's such a bull he hasn't fully understood it yet.”

“But I've talked to people, multiple ones, and they believe that they are putting a slow sedative that they're building up that's also addictive in his Diet Cokes and in his iced tea and that the president by six or seven at night is basically slurring his words and is drugged."

He added: "Now I’m risking my life, by the way, tell you all this. I was physically sick before I went on air."

Mr Jones then claimed: "They drug presidents because the power structure wants a puppet". He said that Mr Trump should have his blood tested by a trusted doctor.