Foreign companies often complain that Chinese manufacturers steal patented technology to make shanzhai, or copycat products, at a cheaper price.

Now a Chinese technology company is making a reverse charge that Made in China inventions are being counterfeited overseas.

To mark World Intellectual Property Day Monday, a local newspaper in Shenzhen, Guangdong Province, reported that some Chinese companies have not protected their own trademarks and copyrights, resulting in huge economic losses due to the theft of patented technology in both local and overseas markets.

The report in Shenzhen-based Jing Bao quoted Fang Zhen, marketing manager of Crastal Technology (Shenzhen) Company, saying that some of the company's patented products were found to be copied overseas and then imported back to China.

Fang said that he discovered that an electronic pot selling on the US market closely resembles one that his company manufactures during a business visit to the United States earlier this year.

"You can barely tell the difference. The only difference is the producer," he was quoted as saying.

Fang said his company is still calculating its economic losses to the US knock-off product.

"We have put a lot of our resources into investigating intellectual property rights infringement overseas. The legal proceedings take a long time and involve a huge amount of money. The cost of protecting our rights is too high," he said.

He added that the company's electronic pot, with a patent pending, should account for 100 percent of the domestic market, yet commands only an 80 percent share. Competing pots are copies of the company's own invention.

Custom officials in Shenzhen told the newspaper that they have seized about 100 million imported products that copied Chinese products last year.

Figures showed that about 42,000 products were submitted for patent protection in Shenzhen, and 20,000 applications were made for patented inventions. But only 757 of the products were registered with customs in 2009.

Feng Jinyue, director of regulations for Shenzhen Customs, said businesses should register their patents with customs to avoid further counterfeiting.

"By doing so, customs could seize the counterfeited products before they go to the market and reduce the loss," he said.

However, more than 70 percent of domestic enterprises have no idea that the policy exists, custom officials said.

Li Xuejun, director of the intellectual property rights department of customs, said foreign companies make up 95 percent of enterprises with their intellectual property rights protected. He said this has been the case since 1995, when China promulgated and implemented its first-ever Regulations on the Protection of Intellectual Property Rights by Customs.

"If enterprises don't register their products with customs, we can do nothing to protect them," Li said.

Separately, figures from the procuratorate in Haidian district, Beijing, revealed that trademark infringement represents 95 percent of all cases charging infringement of intellectual property rights. Among the trademark infringement cases, 30 percent involved counterfeiting the trademarks of local brands.