Charger shock for iPhone user.

A 30-year-old Beijing man is in a coma after he got an electric shock while trying to recharge his mobile phone.

It was the second such incident involving an iPhone in a week.

A 23-year-old woman who died in northwest China last Thursday was found with her iPhone by her side and a charger attached.

In the latest case, Wu Jiantong's sister said he collapsed at around 10pm on Monday after connecting the iPhone 4 he had been using for two years to a charger.

"He shouted 'electric shock' and then fell on the ground," Wu Jianxiang said. He then began trembling and foaming at the mouth while his lips turned purple.

She said she also felt a slight electric shock from her arm to the tips of her toes when she tried to unplug the charger.

Doctors at a nearby hospital said the victim's heart had stopped but they managed to resuscitate him. He was unconscious and in the intensive care unit.

Doctors fear he may have suffered brain damage from a lack of oxygen during the time his heart stopped.

His sister blamed the charger, which wasn't one made by Apple. She said there were no problems with the iPhone and it could still be used.

On online shopping platform www.taobao.com, chargers can cost as little as 4 yuan (65 US cents), while a genuine Apple one costs 149 yuan.

"A non-original charger may use low-quality electric capacity and a safety circuit that lets the 220-volt electric circuit run through the phone and electrocute the user," said Xiang Ligang, a telecommunications expert.

Feng Jianmin, an engineer with an authorized Apple products store in the capital city, also said the electric capacity of non-original chargers could easily be damaged by the 220-volt electric circuit and electrocute the user.

Last Thursday, Ma Ailun, 23, a former flight attendant for China Southern Airlines, was electrocuted in her home in Changji in the Xinjiang Uygur Autonomous Region.

China Central Television later confirmed that she had also been using a charger that hadn't been made by Apple.

Her iPhone 4 had burn marks on both sides and she had burns on her body.

Police said the incident was still under investigation.

In a statement on Ma's case, Apple China said the company would be investigating and cooperating with the police.

It added that it expressed sincere condolences to Ma's family.