SHANGHAI - Residents are calling for a reliable source of heath information since health authorities in Nanjing, capital of Jiangsu province, launched an investigation this week of the once-popular health writer Ma Yueling.

Ma, 48, who was referred to as the "health godmother", has claimed to have cures for serious illnesses including cancer.

The former Nanjing nurse became famous after publishing a book in 2007 named The Wisdom of Staying Healthy, in which she introduced "magic treatments".

On her website, Ma claims to have cured 12 people with amyotrophic lateral sclerosis, a progressive and usually fatal disorder that attacks the nervous system and muscles, by having them eat raw loach.

Nanjing health supervision authorities began investigating Ma this week, and the sale of her books was suspended.

Officials with the Nanjing Public Health Inspection Institute say they are investigating whether Ma is practicing medicine illegally.

"Ma is suspected of treating patients and giving prescriptions without a doctor's license. We are still investigating the case. More information will be given to the public when we get the results," an official from Nanjing Health Bureau told China Daily.

Since Ma's practice is mostly online, rather than in a physical clinic, the investigation has encountered difficulties, the official said.

There have been similar cases in recent years. Last year, a popular Chinese diet therapist, Zhang Wuben, was found to have faked his credentials.

The 47-year-old retired textile worker in Beijing promoted his "magic" diet treatment in lectures, claiming mung beans and eggplant could cure many chronic diseases. Thousands of patients undertook lengthy journeys to receive his therapies, though they could cost up to 2,000 yuan ($309) in consultation fees and months of waiting.

"With growing awareness of health and quality of life, Chinese people are eager to gain information about staying fit," said a retired doctor surnamed Zhang in Tianjin.

In his spare time, Zhang talks about health with neighbors, relatives and friends, and offers them suggestions.

"But in China, most people still have very little knowledge about health, and they need scientific guidance. Reliable medical resources catering to the general public should be established," he said, " If not, unscrupulous businesspeople will do harm to others by publishing unscientific books or offering false advice."

A report on the health literacy of the Chinese people released by the Ministry of Health last year showed that the Chinese people have a low level of health literacy - the ability to read and make informed decisions about health and treatment. The report found that only 7.6 percent of Chinese people have a correct understanding of obesity; 13.95 percent have a correct understanding of sedatives; about 18.7 percent accurately comprehend drug instructions; 17.28 percent know how to deal with bone fractures; and only 4.66 percent have knowledge of preventing chronic diseases.

Mu Jianhua, deputy secretary-general of the China Consumers' Association, said Chinese consumers are in a dire need of a channel for health communication.

Many experts, enterprises and organizations give opinions on health issues in the media daily, but what the public really needs is authorized, scientific, objective and comprehensive knowledge and guidance, Mu said.

"Nowadays, there are many health-related books, TV programs and health information websites. But it is a little bit hard for the people with an average education level to tell which is scientific," said Nanjing resident Chen Liang, 35, who works at a State-owned company.

"So it is necessary that health departments set up broad channels to help public gain more health knowledge," he said.