Apple has posted instructions on its official webpage, advising its customers in China to use genuine power adaptors to charge their devices showing  images of the company's power adaptors and signs to distinguish original ones from the fake devices.

Apple, world leader in mobile manufacturing, was stunned after news of a Chinese airline employee's death by electric shock while answering a call on a charger-plugged iPhone 5 came out two weeks ago. The death of 23-year-old Ma Ailun shocked many people and a series of warning messages spread on social media sites to avoid using the phone while charging. Apple said that it would investigate the death of the woman and cooperate with the authorities.

 The instructions to identify the legitimacy of an Apple power adaptor were uploaded on Apple's official China-based website. It gives detail pointers that can help an average iPhone user identify original products from the fake ones.

"Apple has always put user's security first, and as result all our products have gone through rigorous security and reliability testing," the Cupertino-based company wrote. "They are also designed in compliance with government safety standards around the world."

A second case of electric shock from an on-charge iPhone was reported July 8. A man in Beijing identified as Wu Jiantong, went into coma after he was electrocuted while charging his iPhone 4, according to local Chinese news station.

Tang Fanwei, an engineer at an Apple-authorized company said that the accidents may be a result of using unauthorized chargers not made by Apple. He said that phone chargers compress electricity from 220 volts to 5 volts, which at that small rate does not pose a threat to life. However, some fake chargers do not compress the level of electricity, and directs full 220 volts, which puts human life at risk.

Apple sells power adaptors along with the devices, but a replacement from Apple costs $39. Some unauthorized and substandard chargers come for a few dollars. The images on the Apple website will help consumers make the right choice in identify the original products from fake ones.