Aussie trainer reveals his cheeky remark to King Charles as they chatted just before his horse won a famous race at Royal Ascot

Australian trainer Henry Dwyer has revealed his hilarious conversation with King Charles before his horse won one of Europe's most esteemed races.

Dwyer's horse, Asfoora, stormed home to win the Group One King Charles III Stakes on Tuesday night at Royal Ascot, becoming Australia's sixth winner of the race.

The horse trainer from Ballarat, Victoria was lucky enough to meet the King both before and after the race. 

'I spoke to [King Charles] before the race, we had a good chat and he was terrific actually,' Dwyer told Nine's Today show.

'I'm not a monarchist by any stretch of the imagination, we had a chat and then after the race we compared notes. I think he had a bet on it.

'I said to him before the race, 'it's nice to meet you before the race Your Majesty, but I'd much rather be talking to you after the race', and he took that in the right way.

'He's gone and had a fiver on it or whatever, and everyone is happy.'

Asfoora, which won by a length, had never won a Group 1 race before the race on Tuesday - and Dwyer planned on celebrating.

'We're currently in a taxi on the way into London,' the trainer told Today.

'It might be like a Logies late night... something like that.'

Royal Ascot, a five-day flat racing event held annually at Ascot racecourse in Berkshire, is a major event on the social calendar.

The late Queen Elizabeth II famously loved the race - so much so that, after she died, some thought The Firm's connection with it may end.

But King Charles has continued to attend the event, and was pictured appearing extremely happy at times, with photographs showing the monarch smiling, laughing, and chatting with other racegoers.

Among the other royal attendees were Princess Anne and her daughter Zara Tindall, 43, - who are both famous for their love of horses - as well as Zara's husband Mike Tindall, and her brother Peter Phillips.

Queen Camilla accompanied the King, with the royal couple arriving together in a carriage. Princess Eugenie was also snapped at the event.