After writing down $5.5 billion in the biggest aggregate charge in gold mining history, Newcrest Mining has created shaky ground for competitors, as an internal audit following “selective” disclosure allegations gets under way. The value of Australia’s No. 1 gold miner has plunged 23% since the company’s 2012 results announcement went public on June 7.

Australian Securities and Exchange (ASX) officials asked about the disclosure timing amid “selective briefing of analysts in recent weeks,” ahead of the announcement. This week, Newcrest responded naming former ASX Chair Maurice Newman to conduct an independent review of investor relations practices. The probe is expected to take place over several months.

After citing market conditions as driving the write-down, Melbourne-based company representatives pledged a thorough inquiry. “Newcrest takes its disclosure obligations extremely seriously,” said Newcrest CEO Don Mercer. “Whilst the board is already reviewing events, we have decided to obtain an independent perspective.”

Meanwhile, industry observers noted that, by spending more than $195 billion on acquisitions during boom times over the past decade, other majors could well follow suit. Questionable investment decisions have already created at least half a dozen CEO-level casualties in the last two years.

Affected Newcrest assets lie in Papua New Guinea, the Ivory Coast and Australia. In all, Newcrest’s market value has fallen $2.9 billion in early June to $7.3 billion on June 21—less than the $8.9 billion it spent acquiring PNG’s Lihir Gold Ltd. two years ago.

Harmony Gold Mining Co. officials who partner with Newcrest there, most notably, have also announced writing down their own share of the operation by the end of Q3 2013.