Arsenic has been found in a powdered mineral drink which claims to treat bowel disease, the Food Standards Agency warned today.

Fangocur Mineral Drink contains dangerous levels of the substance and two users in Cheshire are thought to have fallen ill because of the product.

Their symptoms include dizziness, heart palpitations and stomach cramps.

The drink is sold via the internet from Austria, and claims to be a "comprehensive inflammatory bowel disease treatment" for Crohn's disease and ulcerative colitis.

Under UK law this type of medicinal claim cannot be made about food supplements.

Made of "volcanic healing clay", it comes in powder format and must be dissolved in water before ingestion.

The FSA said anyone who has bought Fangocur should not consume it, and those who have and feel ill should seek medical advice.

Arsenic occurs naturally in a wide range of foods at very low levels.

There are two forms, the more dangerous of which was found in Fangocur and is associated with an increase in skin, lung and bladder cancer.

The FSA recommends that exposure to the substance is as low as possible.

A spokeswoman said: "It's being sold in Austria so we don't have any jurisdiction over there. The important thing for us is that UK consumers do not drink it."