Beijing is battling to stamp out illegal sales of 2008 Olympic merchandise on dozens of unauthorized Web sites seeking to cash in on the Chinese public's Games fervor, local media reported on Monday.

Authorities had investigated about 80 commercial and personal Web sites selling fake Olympic merchandise, or lacking licenses to sell the legitimate product, the Beijing Youth Daily said, citing an Olympic e-commerce official.

The supply channels on these illegal Web sites are chaotic, the paper quoted Xie Funing, a spokesman with the Olympic E-commerce Operation Centre, as saying.

Many Web sites lacked legal proof of the origins of their products, while others had exploited consumers' urgency to buy (merchandise) by raising prices and ripping them off, Xie said.

Beijing Olympic organizers have targeted making $70 million from merchandising from the 2008 Games, from a range of about 4,000 products.

But despite authorities making a point of cracking down on Olympic-related forgery, local media reports of police busting fake Games souvenir makers and street peddlers are common.

Law enforcement agencies seized nearly 30,000 finished or half-finished Olympic fakes in the capital earlier this year, and arrested a man in the southern island province of Hainan who cheated Internet users out of a suspected 400,000 yuan ($54,000) through a fake version of the official Games Web site

China is considered the world's most prolific counterfeiter, causing billions of dollars in lost sales to makers of everything from music and movie DVDs, designer clothes and consumer electronics and software.