The World Health Organisation (WHO) says it has received reports of people being admitted to poison centres around the world after taking iodine tablets.

Fears about harmful levels of radiation coming out of the damaged nuclear power plant in Fukishima has seen panic buying of iodine pills in many countries.

Iodine is thought to protect the body's thyroid and glandular system from radiation.

The French government has dispensed half a million tablets to its Pacific territories as a precautionary measure.

But WHO Western Pacific environmental officer, Steven Iddings, says there are already reports of overdoses in countries close to Japan.

"These would be from maybe frightened people who have self-medicated without the advice of a doctor," he said.

"This treatment is really meant for people who are close up, perhaps workers who are associated with the response in Japan."