The man who made Donald Trump a knight of the round table is set to win at least £80,000 if the Republican candidate wins the US election.

Owner of Camelot Castle in Cornwall, John Mappin, who first placed a bet on the GOP candidate when he announced his campaign in June 2015, said he had placed a number of bets on Trump totalling just under £10,000.

The 51-year-old entrepreneur, who made Trump a knight of the round table in February 2016, said he hadn't placed the bets to win money, but to keep a record of his predictions on the outcome of the US election.

"I listened to Trump's words carefully and watched the media and public reaction in America very closely. I was looking at it from the viewpoint of what's going to work and I realised the pundits and the media had gotten it completely wrong and not only was he going to win, but he was going to win in a landslide," said Mappin.

"I am not a gambling person, I have never had an account at William Hill. They had Trump at 33-1 for the presidency and 20-1 at the nomination – and that was back in June, the day he announced, so I started putting bets on and I think I took the entire book at William Hill; one time they let me put on £2,000 and I kept taking the odds up until 4-1, because even at 4-1 I thought it was a no-brainer."

Mappin's early prediction that Trump would win the GOP nomination was based on the algorithm he developed to allow him to predict the outcome of events such as the election.

"It allowed me to isolate and to spot points of leverage which is very, very exciting," he explained. And having placed bets on the presidential hopeful, Mappin went on to research Trump's ideas, becoming an avid supporter.

"I had been paying attention to the election because I had a dog in the fight so to speak. Then it became very clear to me that the British press and some liberal press in the US had been being very dishonest in what they were reporting Mr Trump had said.

"I got hold of his book, which is beautifully written, and I am very clear on what his policies are and any of these unpleasant suggestions that he is racist, or sexist just aren't true, and it just became obvious that some people really hadn't gotten what was really going in America. Trump has connected with people in America in the way nobody had done in a century."

The odds on the GOP presumptive presidential nominee making it all the way to the White House are currently the best they have ever been – with William Hill currently putting a Trump win at 15-8.

"The Trump bandwagon was slow to get rolling, but is positively speeding along now, to the delight of many of those who took a chance and backed him at long odds, including British supporter John Mappin, who stands to collect £80,000 if he wins," said William Hill spokesman Graham Sharpe.

The bookmaker currently has Democrat frontrunner Hillary Clinton at 1-2 and Bernie Sanders at 16-1.