BEIJING-- China will prolong its anti-subsidy probe by one month on potato starch imported from the European Union, said the Ministry of Commerce (MOC) on Monday.

The investigation will be completed before Sept 30, 2011, one month after the previous deadline, since the case was "special" and "complicated," according to a statement posted on the ministry's website.

China launched an anti-subsidy investigation on the imports of EU-made potato starch on Aug 30, 2010 at the request of the China Starch Industry Association.

It is China's first-ever anti-subsidy probe into imports from the EU.

The probe focused on whether the EU members subsidized exports of potato starch to China, and if so to what extent the subsidies had harmed domestic industries.