President Trump has repeatedly accused Chinese firms of copyright theft.

The issue is at the heart of the current trade friction between China and the United States.

But Chinese firms are fighting back in American courts and winning.

Just over a decade ago, an electrical component firm in eastern China faced an uncertain future when it was sued in a US court over intellectual property rights.

The Chinese company fought the action and was eventually able to prove that the plugs and other devices manufactured in China were not copies.

Al Jazeera's Adrian Brown reports.