China's Ministry of Commerce will issue a preliminary ruling on its anti-dumping and anti-subsidy investigations into imported polysilicon from the United States, the European Union and South Korea on Feb 20, the 21st Century Business Herald reported citing an unnamed source.

China launched a probe on Nov 27 to determine whether retroactive duties should be levied on imported solar-grade polysilicon from the three countries.

The newspaper quoted unnamed senior officials in the polysilicon business as saying that leading exporters, including Wacker Chemie AG — which produced 95 percent of EU's polysilicon exports to China in 2012 — rushed to export the material to China during the investigation period.

Chinese imports of polysilicon increased 36 percent year-on-year in 2011 to 64,600 tons worth more than $2 billion. Imports are expected to reach a record high of 80,000 tons in 2012.

Polysilicon, or polycrystalline silicon, is a key component of solar panels.