The Royal Canadian Mint has demanded that its Australian counterpart destroy a set of coloured coins celebrating the popular children’s book Possum Magic amid a legal battle over rights to the process used to create them.

A lawsuit filed in December in Australia’s federal court alleges that the Royal Australian Mint had – without permission – used a patented method of printing colour on metal to print 500,000 commemorative Remembrance Day $2 coins featuring a red poppy.

The Canadians said they had flagged the patent issue two years earlier, only to have their concerns met with an assertion that the method being used in Australia was “sufficiently different to have not infringed” the patent.

The Canadian mint eventually took its complaint to the Australian courts, demanding that any coins not yet in circulation be either turned over or “destroy[ed] under supervision”, according to the National Post.

The lawsuit launched by the Canadian crown corporation also seeks to force Australian mint – which is part of the Australian government – to surrender any profits and pay damages.

The Royal Australian Mint’s Possum Magic coins. Photograph: Royal Australian Mint.

Recently, the Canadian mint expanded its lawsuit to include several other $2 coins, including a 2017 release featuring designs from Possum Magic and Olympic-themed coins.

While the coins in question include 12 colourful designs printed on an estimated 15m coins, the Canadian mint said it is not seeking the destruction of any coins already in circulation.

Their demands have been countered with another lawsuit – this week the Australian government filed a counter claim asking that the Canadian patent be declared invalid on the grounds that it is not enough of a “novelty” over what has been done previously.

The duelling mints are also business rivals who rely on developing new technologies in order to secure contracts around the world. In recent years, the Canadians’ list of clients has ranged from Indonesia to the United Arab Emirates.

The Royal Canadian Mint has said that its lawsuit is aimed at protecting what sets it apart on the global market. “As a crown corporation mandated to operate in anticipation of profit, our technologies are vital to maintaining our competitive standing, and the mint undertakes all steps necessary to protect its intellectual property rights,” a spokesperson told the National Post earlier this year.