The world biggest mining company, BHP Billiton, has taken the wraps off possible corruption at all the exploration projects.

The issue mainly involved "interaction" with Government officials and details from the same had been effectively passed on to the SEC, or the Securities and Exchange Commission.

Where the alleged violations had occurred was not revealed by BHP, but it did say that it was not China, where four staff members of BHP's rival Rio Tinto were recently jailed for corruption and bribery.

BHP stressed that the projects involved in the probe were "small" and not active anymore.

In a statement, the company said that it had "disclosed to relevant authorities evidence that it has uncovered regarding possible violations of applicable anti-corruption laws involving interactions with government officials".

BHP also added that the company is completely cooperating with the officials, and is also conducting an internal investigation.

Shares of the company fell by 47.5 pence, or 2.2%, to 2,132.5 pence in London trading at 11:38 AM. Earlier in Sydney, the stock had dropped by 0.2%.