made in the country -- are highly popular, although it faces fierce competition from South Korea's Samsung.
State media have carried a series of attacks against Apple, with the People's Daily, the Communist Party's official mouthpiece, running critical items for five consecutive days over alleged double standards in customer service and returns policies.
Apple has denied those accusations in statements to Chinese media but the condemnations have continued unabated, with the newspaper urging consumers to "strike away Apple's unparalleled arrogance" in one of its commentaries.
The State Administration for Industry and Commerce (SAIC) has asked trading standards bodies across the country to step up "contract supervision" on electronics manufacturers "such as Apple", the People's Daily said Friday.
"Local governments are required to... investigate and punish illegal activities in accordance with the law," it quoted the SAIC as saying in an official note.
An SAIC spokesman who declined to be named confirmed the existence of the document to AFP but declined to disclose details on the grounds it was for internal circulation.
The People's Daily articles follow reports on state broadcaster CCTV, but users of China's Twitter-like weibos have been split, with some backing Apple and saying state-owned Chinese firms were more deserving of targeting for poor service.
Scepticism about the media attack among web users rose after a prominent singer condemned the firm but his post included a line on when it should be sent, heightening speculation that it was an organised campaign.
Columnist and microblogger Lian Peng said he bought a new iPad Friday "on purpose" and will "seriously consider buying an iPhone 5".
"I don't fancy electronic items. But I feel embarrassed if I don't purchase after seeing the bombardment of advertising jointly staged by CCTV and the People's Daily," he wrote.
But any underlying motive behind the attacks remains unclear.
No-one from Apple's China office was available for comment Friday.
The California-based company has also been embroiled in legal disputes in China over alleged intellectual property rights infringements.
Apple appeared in a Shanghai court on Wednesday accused by a Chinese firm of infringing its patent for voice recognition software used for the iPhone's "Siri" personal assistant.
On Friday Hong Kong's South China Morning Post newspaper said a state-owned Shanghai animation film studio had sued Apple in a Beijing court for allegedly selling its movies without approval, seeking compensation of 3.3 million yuan ($530,000).
The court did not respond to a request for comment from AFP Friday, while the film studio declined to do so.
The legal challenges come after Apple last year paid $60 million to Chinese computer maker Shenzhen Proview Technology to settle a long-running dispute over the "iPad" trademark, whose ownership was claimed by both companies.