By Omer Farooq
BBC News, Hyderabad
The Indian Medical Association (IMA) has decided to take legal action questioning the scientific basis of a 150-year-old cure for asthma.
Fish is valued for its for food and medicinal values
Known in the southern state of Andhra Pradesh as fish medicine, the cure is used by hundreds of thousands of patients every year.
In recent years, the medicine has gained tremendous popularity.
About half a million people visit Hyderabad every June to consume the medicine which is taken with live fish.
An official of the IMA, CL Venkat Rao, told journalists that the association will issue legal notices to the state and central government for their failure to verify the scientific basis and the contents of the medicine.
He said the Andhra Pradesh High Court had last year asked the government to find out the contents of the medicine but so far nothing had been done.
Fish medicine is highly sought after in India
The IMA has decided to take court action because it says the family in Hyderabad which owns the medicine is preparing to administer it again this year - starting on 8 June.
Bathini Harinath Goud, the spokesperson of the Hyderabad-based family, says the formula of the "herbal medicine" was given to his great grand father Veeranna Goud by a sage in the Himalayas in 1854.
He says that since then the family has been distributing the medicine to people free of charge.
The family say they cannot reveal the formula, because if they do so, the medicine will lose its efficacy and others will commercially exploit it.
But the IMA says tests at a private laboratory in Hyderabad last year revealed that it had steroids, heavy metals, mercury and other ingredients which could be harmful to asthma patients.
Dr Rao says the presence of these steroids and heavy metals can harm kidneys, cause impotence and lead to intestinal and bone marrow damage in addition to other diseases.
The IMA said that in some cases, it can aggravate the medical condition of asthma patients.
Legal notices will be issued to the Andhra Pradesh government, Dr Rao said, in addition to the heads of police, water supply and the central ministry of health and family welfare.
The IMA says the action is necessary to stop what it terms "government patronage" of the event.
It has questioned the rationale of the government spending nearly $2.3m on the event every year, providing food, water and other help for the tens of thousands of people who come to be treated.
However, the Goud family dismissed the claims by the IMA.
"Doctors keep saying such things against us. We are not worried about what they are saying," a family statement said.