The State Administration for Industry and Commerce (SAIC) has launched the nationwide investigation, ChinaNews.com reported on its website citing unidentified sources.

SAIC and Tetra Pak officials in China could not be reached for comment.

The National Development and Reform Commission (NDRC), the top economic planning agency, is already investigating six milk-powder producers including Nestle (>> Nestle SA) and Danone (>> DANONE), for possible price-fixing and anti-competitive behavior. Both Nestle and Danone have responded by saying they would cut prices.

The NDRC is also investigating costs and prices charged by drugmakers, including units of GlaxoSmithKline (>> GlaxoSmithKline plc) and Merck (>> Merck & Co., Inc.).

Tetra Pack entered China in 1972 and its clients include China's biggest milk and beverage producers including China Mengniu Dairy Co Ltd (>> China Mengniu Dairy Company Limited), Inner Mongolia Yili Industrial Co (>> Inner Mongolia Yili Industrial Group Co.) and Uni-president China Holdings Ltd (>> Uni-President China Holdings Ltd.).

(Reporting by Samuel Shen and Kazunori Takada; Editing by Stephen Coates)