New Delhi, Sept. 4: An advertising industry watchdog, alerted by a doctor, has described as "misleading" and "unsubstantiated" a water purifier advertisement that claims the product is the first choice of a doctor and yields the purest water.

The advertisement by Kent RO Systems, which features Hema Malini, describes one of its purifiers as "Doctor's 1st choice RO Purifier" and carries the line " sabse shudh paani" (the purest water).

A senior official with Kent RO told The Telegraph the company had decided to withdraw the advertisement.

Kerala-based ophthalmologist Kankokkaran Vadakke Babu had complained to the Advertising Standards Council of India (ASCI) that the advertisement was misleading consumers by creating an impression that doctors had endorsed the Kent RO purifiers.

"Doctors are not allowed to endorse any commercial product - that would be a violation of the code of ethics we're expected to follow," Babu said.

His complaint cited the Medical Council of India's rules of ethics that prohibit physicians from approving, recommending or endorsing any "drug, medicine, surgical or therapeutic product, or apparatus or appliance or any commercial product".

The ASCI's Consumer Complaints Council examined the complaint and the response from the company, which appeared to cite a study in its defence.

The watchdog questioned the study's methodology and the research credentials of the "Women's Health Organisation", which conducted it. It underlined that the study related to the "perception" of brands and did not involve novel research.

It observed that the claim "Doctor's 1st choice RO Purifier" had not been substantiated, and that the company had failed to prove the "purest water" claim as it had not compared its water samples with those from competitors' products.

To the company's claim that water purity from its purifiers met IS:10500 quality standards, the watchdog said: "This is not valid defence, it only shows the water is pure as per stated standard."

Babu had five years ago pushed the Medical Council of India's ethics panel into recommending the temporary de-licensing of two doctors who had allowed the Indian Medical Association to endorse brands of juice, oats and a mosquito-repellent skin lotion.