"King Michael" enjoys a beer after a day at work on the farm

Dr Michael Jones says Queen Elizabeth's claim to the throne is false because her distant ancestor, Edward IV, was illegitimate.

He concludes that the crown should have passed instead through another royal line which today ends at British-born Michael Abney-Hastings, 62.

"King Michael" said he was shocked by the news - but remained a republican.

He said it was "unlikely" that he would go to Buckingham Palace to claim the crown.

Archer rumours

Dr Jones' thesis, explored in a recent television documentary, suggests that Edward IV, who reigned from 1461 to 1483, was conceived when his parents were 160 kilometres apart.

His "father", Richard Duke of York, was fighting the French at Pontoise, near Paris, while his mother, Lady Cicely Neville, was at court in Rouen.

She was said to be spending much of her time in the company of a local archer with whom she was rumoured to be having an affair.

Dr Jones said Edward IV's alleged illegitimacy means the crown should instead have been passed down the Plantagenet line - ending at Mr Abney-Hastings.

The unlikely heir lives in Jerilderie, a small town 640km southwest of Sydney, in New South Wales, where he moved from the UK as a teenager.

"I don't think it's really sunk in yet," he said.

The farm forklift truck driver said he had already known he was descendant of the Plantagenet family - and 14th Earl of Loudon in Scotland - but never guessed he could be a contender to the throne.

"I'm definitely a republican," he said.

"As much as I love England, I honestly feel in this day and age Australia should be standing on its own feet in everything, and that means we have to be a republic. In the last referendum we had on it, I actually voted to become a republic."

God save King Michael?

He said it was "very unlikely" he would go to London and demand entry at Buckingham Palace. But he quipped, "I'll hedge my bets."

Mr Abney-Hastings, who is widowed, said he was treated the same as ever by friends and family - except on Christmas Day, when he was welcomed to dinner with a rendition of God Save the King.

He said his eldest son had not mentioned inheriting his crown, and warned: "He'll have to wait. It's not available till I go."

Buckingham Palace, meanwhile, refused to respond specifically to the claims, saying any conclusions reached in the television documentary were "a matter for the programme makers".