Despite its insistence of continuing to dump mine processing wastes into the sea, Newcrest Mining Ltd said on Thursday that it has a solid environmental track record even if its recent acquisition of Lihir Gold puts that record into serious scrutiny.

The $10 billion merger transformed Newcrest Mining into the world's third largest producer of gold in terms of market capitalisation and added to its existing assets Lihir's rich island gold mine source in Papua New Guinea.

ABC recently covered the Lihir Island gold mining operations and raised concerns on the manner tailings were disposed off directly into the sea.

Newcrest chair Don Mercer did not touch on whether the company would review and revise such mining practices but he downplayed the alleged environmental risks of dumping wastes directly to the open ocean, calling it as "marginal issue."

Mr Mercer claimed that the story aired by ABC was bereft of any research support, asserting that Newcrest is serious on preserving its reputation "and we frankly do a responsible job, and that is the case of our predecessors at Lihir Island."

Likewise, Newcrest chief executive Ian Smith assured the company shareholders that the tailing dumping into the sea is environmentally safe, arguing that "we introduce the tails into the sea at a depth of 115 metres, well below the mixing zone."

As such, Mr Smith said that the practice would continue as he cited that even independent marine experts have already verified and certified that the "ongoing monitoring has not shown any material metals concentration in the food chain."

Newcrest Mining also informed its shareholders that fiscal 2010 proved to be a record year for the company with the addition of the Cadia East gold project in New South Wales, the success of its PNG exploration and the realisation of the Lihir Gold takeover.

That fiscal year, according to Mr Mercer, "was a very successful year, culminating in record gold production, record profit and record cash flow for the company."