Developed as a large underground panel cave gold mine, Cadia East is claimed to be the largest metalliferous underground mine in Australia.

The company said it has invested $2bn develop the first Cadia East panel cave, associated infrastructure and expand Cadia’s processing capacity from 24 to 26 million tons a year.

Work on the Panel Cave 2 is underway with commercial production expected to start in fiscal 2015.

Newcrest managing director and CEO Greg Robinson said: "Cadia East is a large, long life asset and a cornerstone of our Company’s strategy.

"With an approved mine life of 21 years, Cadia East will deliver significant economic benefits to the local community, the workforce and suppliers, local, State and Federal governments, and of course Newcrest’s shareholders for the long term."

Cadia East has 2.8 billion tons of ore estimated to contain 37 million ounces of gold and 7.5 million tonnes of copper. As of March 2014, it has produced 230,000 ounces of gold and 15,000 tonnes of copper.

Newcrest said Cadia Valley Operation’s overall production is expected to be about 700,000 ounces of gold in 2016 and higher again in 2017.