A flight attendant with China Southern Airlines was electrocuted in her home when making a call with her iPhone5 on Thursday. Photo:weibo.com

A woman has claimed her 23-year-old sister was killed by an electric shock from her iPhone5 while it was being charged.

Ma Ailun, who worked as a flight attendant for China Southern Airlines, is reported to have been electrocuted on Thursday while she was making a call with her smartphone plugged in, the Guangzhou-based Yangcheng Evening News reported on Sunday.

Police in Changji, Xinjiang Uyghur Autonomous Region, where the victim and her family reside, confirmed with the Global Times on Sunday that they have received reports from the victim's family and started an investigation, but declined to disclose further details. 

Ma's elder sister first revealed details of the incident on Saturday via Sina Weibo.

"(I) hope that Apple can give us an explanation. I also hope that all of you will refrain from using your mobile devices while charging," her post read.

The phone was bought in December, and was still under warranty. It was being charged with the original Apple charger, she wrote. 

The Weibo post has gone viral, with Web users warning others of the potential dangers of using phones while they are charging, while others point out the charger's output is actually quite low.

Changji police told the Nanjing-based newspaper Modern Express that Ma was killed by an electric shock, according to their forensic report, but said they were not sure whether the shock came from the charger.

The output of the charger is 5 volts, which is not enough to electrocute a person, the Yangcheng Evening News quoted an electrical expert as saying.

Apple said on Sunday in a statement that the company felt "deeply sorry for the unfortunate accident" and expressed condolences to the victim and her family. They will cooperate fully with the investigation.

Last Tuesday, a man in Chongqing awoke to find his iPhone4 smoldering next to him on his pillow, caused by faulty parts, local police said.

Apple has found itself under a torrent of criticism this year in China, after reports revealed it had double standards regarding its warranty policy in China. Apple later apologized and changed its after-sales procedures in the country. 

Xinhua contributed to this story