GUANGZHOU, Feb. 25 -- Three smuggling gangs have been busted for bringing over 72,000 tonnes of used laptops and parts into China illegally, customs have said.

In cooperation with police, customs authorities in Guangdong Province, Liaoning Province and Tianjin Municipality arrested 54 gang members in a raid on Jan. 5, an official with the General Administration of Customs told Xinhua.

More than 500 police took part in the raid and they seized 185 shipping containers, as well as more than 200 additional tonnes of products at the site.

Investigations showed the gangs had smuggled more than 72,000 tonnes of "e-trash" since 2013, the largest quantity ever discovered, which was hidden in over 2,800 containers. The e-trash came from Japan and some European and American countries, said the official.