BHP Billiton Ltd. (BHP.AU) Tuesday said it is unaware of any investigation by Chinese authorities into its operations in China.

"BHP Billiton is unaware of any investigation," a BHP spokeswoman told Dow Jones Newswires.

The miner's comments come after China last week detained four Rio Tinto Ltd. (RTP) executives including the head of the company's Chinese iron ore division, Stern Hu, and accused them of bribing steelmakers to obtain state secrets.

-By Ross Kelly, Dow Jones Newswires; 61-2-8235-2957; ross.kelly@dowjones.com