BHP Billiton has been told it could face "enforcement actions" over a long-running corruption inquiry by American regulators.
In a surprise move, BHP released a statement on Friday revealing further conversations have been held with the US Department of Justice and the US Securities and Exchange Commission in recent times. The mining company has been told it could soon be facing charges of some kind.
"As a part of the US process, the SEC and DOJ have recently notified the group of the issues they consider could form the basis of enforcement actions, and discussions are continuing," BHP said.
"The issues relate primarily to matters in connection with previously terminated exploration and development efforts, as well as hospitality provided as part of the company's sponsorship of the 2008 Beijing Olympics."
Fairfax Media has reported extensively on the corruption inquiry, which is believed to have scrutinised the hospitality, gifts and largesse bestowed upon Chinese officials during the 2008 Games.
BHP assisted the inquiry several years ago by handing over evidence that suggested possible violations of rules that govern interactions with foreign government officials.
During one report in March, BHP reportedly expressed confidence that "our Olympics activities complied with all applicable law".
It is believed BHP has also been investigated over an attempt to secure a bauxite asset in Cambodia, and certain business activities in Western Australia.
It has been reported that a public official in WA could be dragged into the probe.
In recent months, the American process been complemented by an Australian Federal Police investigation, and BHP said on Friday it would continue assisting the authorities.
"In light of the continuing nature of the investigations it is not appropriate at this stage for BHP Billiton to comment further or to predict outcomes," the company said.
"BHP Billiton is fully committed to operating with integrity and the group's policies specifically prohibit engaging in unethical conduct."
"BHP Billiton has what it considers to be a world class anti-corruption compliance program."
BHP shares fell 46¢ to $36.87 on Friday, on a day when most miners lost ground.
The investigation highlights the challenges companies from the developed world face when working in developing nations where corruption may be far more common.
Rio Tinto also came to grief in China when one of its employees, Stern Hu, was jailed for paying off Chinese officials.
At one stage, earlier this year, more than 30 Australians were in Chinese jails.
Rio Tinto subsidiary SouthGobi Resources has also faced corruption allegations in Mongolia. Australian lawyer Sarah Armstrong was detained in Mongolia for close to two months in the stoush.
BHP Billiton chief executive Andrew Mackenzie will likely be asked about the investigation when he presents the company's full-year results on Tuesday.
BHP is expected to report an underlying profit of just over $US12 billion ($13 billion) on Tuesday; more than 40 per cent lower than the result reported in 2011.