BEIJING -- China's Ministry of Commerce announced Thursday that it will extend an anti-dumping probe into imports of solar-grade polysilicon, a material used in solar equipment manufacturing, from the European Union (EU).

Given the complexity of the case, the ministry decided to extend the investigation by another half year to end on May 1, 2014, a statement on the ministry's website said.

The ministry first launched the investigation on Nov 1, 2012 in response to requests filed by Chinese polysilicon manufacturers amid an import surge and price decline of European products.