Almost all of the herbal dietary supplements tested in a Congressional examination included some quantities of lead and other pollutants, and some supplement vendors made illicit claims that their products can treat cancer and other ailments, examiners discovered.

The investigators found that the amounts of heavy metals, comprising mercury, cadmium and arsenic, did not surpass limits deemed hazardous.

But, 16 of the 40 supplements that were examined had pesticide traces, which seemed to go over authorized limits, the investigators found.

In some instances, the Government has not fixed acceptable levels of these pesticides owing to dearth of scientific research.

Investigators learnt that a minimum of nine products, which evidently made illicit health claims, comprising a product including ginkgo biloba, which was branded as a cure for Alzheimer's ailment and a product having ginseng tagged as a treatment to avoid diabetes and cancer.

They also revealed that a salesman at a supplement specialty store stated that a garlic supplement can be used in place of blood pressure drug.

Any product that claims to cure, treat, put off or diminish a sickness is regarded as a drug and must undergo stern authoritarian evaluations.

The report that was compiled by the Government Accountability Office was presented to The New York Times and will be unveiled at a Senate hearing on Wednesday.