BHP Billiton Ltd. (BHP) hasn't been approached by China about any potential investigation into trading practices at its iron ore division, a person familiar with the matter said Tuesday.

Some analysts and market watchers have speculated that BHP Billiton could also be under investigation by Chinese authorities after they last week detained four Rio Tinto Ltd. (RTP) executives and accused them of bribing steelmakers to obtain state secrets.

"BHP has not been approached about any such investigation," the person said.

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