China has destroyed millions of illegal copies of DVDs and CDs in a national anti-piracy campaign, believed to be the largest of its kind ever held.

In the capital city Beijing, the Anti-Pornography and Anti-Illegal Publications Work Leading Group collectively destroyed pirated discs by putting them through grinders.

The action took place on Sunday, just before World Intellectual Property Day on April 26.

Lin Binjie is the group's deputy director.

"Through today's large-scale destructon activities, we hope that we can further show the world the Chinese government's high determination to protect intellectual property and crackdown harshly on piracy."

Similar actions were seen in other cities across the nation on the same day.

Nearly 50 million unauthorised items were destroyed nationwide.

Officials said that more than 4,000 people were convicted of product piracy last year. They've also promised special efforts to protect Olympic-related trademarks.