Australian one cent coins were withdrawn from circulation in February 1992. However, they were not demonetised and are still legal tender.
In 2006, the Royal Australian Mint produced some for mint sets (regular coins and proofs), celebrating the 40th anniversary of the denomination.
Unlike all other coins of the same year, silver proofs have Her Majesty's "Second Portrait" (by Arnold Machin), which was last used in Australia in 1984. They have a diameter of 17.53mm, weigh 2.6g and are of 0.999 purity (0.0835 oz. ASW).