SMALL but powerful magnets are used in toys including Mattel Polly Pocket dolls (above) and Mega Brands' popular Magnetix.

These magnets - which have become more commonly used in toys as prices dip - can be 20 times more powerful than the average refrigerator magnet.

They can, for example, make Barbie's dog chase after her or Polly Pocket's clothes easier to put on and take off.

More than 15 million toys have been recalled in the United States since last year because they contain such magnets.

Swallowed magnets have led to the death of at least one child and dozens of serious injuries.