BEIJING -- In yet another attempt to suppress advertisements that continue to stain the Chinese media despite being labeled "illegal", China's commerce and drug watchdog has blacklisted seven particularly egregious offenders.

The seven advertisements on the blacklist published Thursday by the State Administration for Industry and Commerce and State Food and Drug Administration (SFDA) are all for drugs and medical equipment.

According to the two administrations, the manufacturers and retailers involved were punished last year for violating China's advertising law -- providing false information or exaggerating the benefits of their products.

But the sanctions have had no visible effect on the companies' behavior.

Some of the advertisements misled customers with endorsements by self-appointed experts.

Food and drug administrations at all levels have been urged to strengthen supervision and go as far as banning the products if their manufacturers and retailers continue to post illegal advertisements.

But part of the problem seems to lie with the largely government-owned media who continue to accept "illegal" advertisements.

A survey by the SFDA of 466 newspapers and 55 local TV stations from January to November last year uncovered 48,990 illegal advertisements for drug products.