The world's most popular cell phone producer, Apple Inc., has adopted differential policies for repair and return services in China, China Central Television (CCTV) has reported.

In this second-largest market for Apple, its unfair or discriminative provisions include shorter warranty periods compared with that of other countries, using refurbished parts for repair and averting after-sale obligations, according to a consumer protection TV show broadcast by CCTV on Friday, or the International Day for Protecting Consumers' Rights.

Consumers who asked for replacement of iPhones, Apple's flagship mobile product, due to quality defects during the warranty period always found that their renewed iPhones still kept the old back cover, the program said.

In addition, the guarantee period was not extended to another year as stipulated in China's after-sale regulation but remained the same as with the former unit.

Under Chinese law, replaced mobile phones should be covered by another one-year guarantee period after the replacement, which, for producers, can mean heavy burdens on their after-sale services that they are unwilling to bear.

A staff member from an Apple customer service center in China told CCTV that the "old back cover" tactic was used to shirk the repair obligation as the changed unit could not be defined as a replacement while it still incorporated a former part.

She implied that the practice resulted from the company's consideration of prompting buyers to spend more on Apple's products.

In sharp contrast with the situation in China, Apple consumers in other parts of the world including the United States, Australia, the Republic of Korea and the European Union meet no such awkwardness in their after-sale process.

However, Apple's regulation violations in China also extend to other products from the company such as its iPads.

Apple's repair policies led to a number of complaints in 2012 and caused some provincial consumer watchdogs to include the firm on a "company integrity" blacklist.

In August, Apple fine-tuned parts of the controversial repair policies but some unfair practices still remain.

In an earlier announcement, the China Consumers' Association, the country's top consumer watchdog, noted Apple could further improve its efforts to guarantee the legal rights and interests of its fans as "most unfair clauses have still not been addressed or corrected."

Apart from the Apple case, the program also revealed consumer rights infringements including defective direct-shift gearboxes in Volkswagen cars, substandard imported food, deceptive medical advertising and personal information leaks through mobile devices and the Internet.

The TV show, broadcast for 23 consecutive years every March 15, has brought numerous scandals to light in recent years.