Global miner BHP Billiton revealed on Wednesday possible violations of anti-graft laws inside the company, in another blow to the mining industry's tarnished image.

BHP Billiton said it had uncovered the possible violations, relating to exploration projects, after requests for information from the U.S. Securities and Exchange Commission (SEC).

The announcement comes soon after staff from main rival Rio Tinto were jailed for bribery in China in a case that shed an ugly light on the mining industry, which once again in the grip of a commodities boom fueled by Chinese demand.

BHP Billiton revealed the investigation in a single paragraph in its third-quarter exploration report and said in a separate email that the probe did not relate to activities in China.

The company has disclosed to relevant authorities evidence that it has uncovered regarding possible violations of applicable anti-corruption laws involving interactions with government officials, it said in its exploration report.

Accordingly, the company is cooperating with the relevant authorities, including conducting an internal investigation, which is continuing. It is not possible at this time to predict the scope or duration of the investigation or its likely outcome.

In a separate email, it added: We are limited in what we can comment on as the matter is still under investigation.

However, we can confirm that the SEC's requests for information primarily relate to certain terminated minerals exploration projects and not any activity in China, BHP Billiton's marketing activities or the sale of any of the company's products.


In its production report also released on Wednesday, BHP Billiton posted an 11 percent rise in third-quarter iron ore production, trailing a faster expansion in iron ore output at Rio Tinto which reported 39 percent growth for the March quarter.

BHP Billiton also reported a heavy fall in copper output, which was down 19 percent in the March quarter from a year earlier, partly due to disruptions at its Olympic Dam mine.

Production from Olympic Dam, the world's fourth largest copper deposit, was cut by 75 percent in October due to a mining accident that shut the main shaft. The shaft is being repaired and is due to return to normal operation by end-June.

(Reporting by James Regan; Editing by Mark Bendeich and Balazs Koranyi)