BHP Billiton, the world’s largest mining company, has uncovered potential violations of anti-corruption laws in dealings with government relating to its exploration activities.

The case is under investigation by the US Securities and Exchange Commission, following the conviction of four employees of Rio Tinto in China last month for receiving bribes and stealing commercial secrets.

BHP and Rio Tinto are currently seeking regulatory approval for a $116bn Australian joint venture.

Asian mills are protesting against the venture, saying it would give the pair undue influence on the price of iron ore.

BHP said the exploration projects in question had been terminated before December 2008 and are relatively small and are unrelated to any activities in China.

Meanwhile, Australian Foreign Minister Stephen Smith said the government would hold off any inquiry into the case for now.