The Consumer Council has called on consumers to watch their chocolate intake, saying all 29 samples it tested were found to contain traces of the heavy metal cadmium, with one even exceeding permitted European Union levels.

The watchdog tested 20 dark chocolate and nine milk chocolate samples, and found that the cadmium level in “Amedei Blanco de Criollo Extra Dark Chocolate 70%” exceeded levels set out in the European Commission Regulation by 17.1 percent.

The council’s chief executive, Gilly Wong, said consuming excessive cadmium over a prolonged period of time can cause kidney damage.

"If you are talking about the impact of cadmium, it is widely used in different industries but if you [have a] long-term intake of cadmium, it could hurt your kidney," she warned.

Wong noted that an adult should only eat 100 grams of pure chocolate a week.