WELLINGTON (AFP) - An elderly New Zealand anti-royalist was fined on Monday over a plan to hurl manure at Britain's Prince Charles and his wife Camilla during their visit to Auckland last year, reports said.

Sam Bracanov, 77, pleaded not guilty to preparing to commit an assault after his arrest on Nov 12 as the royals readied to meet crowds on the Auckland waterfront while touring to mark Queen Elizabeth II's diamond jubilee.

Judge Anne Kiernan found Bracanov guilty in the Auckland District Court and ordered him to pay a NZ$200 (S$203) fine plus NZ$132 in expenses, the New Zealand Herald reported.

Fairfax Media reported that Bracanov, who police described as "a known anti-royalist", was visited by officers ahead of Prince Charles' arrival and told them he intended to throw manure at the royals.

When warned against the plan, he reportedly responded: "Royal family? I call them the smell family." After his initial court appearance in November, Bracanov told reporters he was protesting at Prince Charles' privileged position.

"He didn't qualify with his brain, he qualified with his body, and what (the) body produce(s) goes to toilet, so I would hit him with what goes to toilet," he said.

He reportedly attempted a similar action when the prince visited in 1994, trying to spray air freshener at him to "remove the stink of royalty".

In 1988, he threw a bucketful of horse manure at a car carrying King Juan Carlos of Spain on a state visit to New Zealand and was convicted of disorderly behaviour, Fairfax Media reported.

Radio New Zealand said the pensioner would pay off his fine in weekly instalments of N$10.