Newcrest received four claims last month and GCR has launched a fifth separate action.
GCR holds exploration licenses near Newcrest's massive Cadia mine. The claims related to permitting, the award of exploration licenses to Newcrest and an alleged breach of confidence in respect of GCR exploration technology.
The latest claim seeks to challenge the validity of two of the mining leases held by Newcrest for Cadia Valley, which were granted in 2000 and 2001.
The New South Wales Minister for Resources and Energy was a co-respondent in three of the initial claims and was the first respondent in the latest claim.
Eddie Obeid was the minister at the time the licenses for Cadia were granted. He is now the centre of a corruption inquiry.
Newcrest dismissed the action as GCR looking to expand its holdings by challenging existing tenure.
Not much is known about GCR, but it had been widely reported that the company was backed by former Rio Tinto boss Leigh Clifford.
Newcrest said as with the four earlier claims, it believed the newest court action to be without merit.
"Newcrest will be vigorously defending the action and considers that, as with the other four actions, the matter is not material to Newcrest and will not adversely impact operations at Cadia Valley," the company said.
It added that the matters did not affect normal operations at Cadia or the $A2 billion Cadia East expansion project, which is under development.
Preliminary production guidance for Cadia East for the 2013 financial year remains at 400,000-500,000 ounces of gold and 50,000-60,000 tonnes of copper.
When it reaches full production around 2016, it will produce about 700,000 to 800,000 ounces of gold and 100,000 tonnes of copper annually.