Chemical analyses have found that high levels of a chemical that causes tumors in animals are present in drinks made by Coca-Cola and PepsiCo, according to a report by a consumer advocacy group.

Going by a study published by the Center for Science in the Public Interest (CSPI), the substance 4-methylimidazole (4-MI) has been found in high levels in products from both Coca-Cola and Pepsico.

Samples of Coca-Cola, Pepsi-Cola, Diet Coke, Diet Pepsi, Dr Pepper, Diet Dr Pepper, and Whole Foods 365 Cola from Washington, D.C.-area stores were collected for the study by CSPI. The chemical was included on California's list of carcinogens.

Coke and Pepsi, with the acquiescence of the FDA, are needlessly exposing millions of Americans to a chemical that causes cancer, said Michael F. Jacobson, the Washington-based group's executive director, in a statement.

The coloring is completely cosmetic, adding nothing to the flavor of the product. If companies can make brown food coloring that is carcinogen-free, the industry should use that, he said.

The FDA needs to protect consumers from this risk by banning the coloring, he added.

The CSPI has asked the Food and Drug Administration to ban caramel coloring agents that contain 4-MI. The FDA is reviewing the complaint given by CSPI and has stated that there's no immediate risk to consumers from the substance.

A consumer would have to consume well over a thousand cans of soda a day to reach the doses administered in the studies that have shown links to cancer in rodents, said Doug Karas, an FDA spokesman, in a statement.

Meanwhile, the American Beverage Association stated that there was no evidence the chemical could cause cancer in humans. This is nothing more than CSPI scare tactics, and their claims are outrageous, it added.