An estimated 40 per cent of mainland cable television operators have stolen the World Cup TV signal from China Central Television (CCTV).
Among 39 cable TV networks in the country screened the opening match between France and Senegal on Friday, only 22 being authorised to do so, advertising companies have found.
Advertising firms also claim many of the networks have pulled advertisements booked with CCTV-5, the national sport channel, and replaced them with their own.
These companies said a number of networks screening the soccer illegally and networks replacing authorised adverts were operators broadcasting in major cities, which have a high viewership.
According to Steven Chang, vice-president of Zenith Media China, which represents advertisers such as Procter & Gamble, seven out of the 39 networks have replaced the CCTV adverts.
Experts said many of the unauthorised networks had been offering World Cup advertising packages despite being illegal operators.
