SAN FRANCISCO - Marvel Enterprises Inc. has halted shipments of its Chinese-made Curious George products to retailers and says it will issue a recall if testing confirms allegations the items contain illegally high amounts of lead.

The Oakland-based Center for Environmental Health sent Marvel a legal notice Wednesday, alleging it had purchased a Curious George doll that contained 10 times the legal maximum of lead at a Toys "R" Us store.

Marvel spokesman David Collins said the company has been in touch with the CEH, asking for details of its testing.

He said if Marvel's independent testing confirms those results, "we will move immediately to initiate a voluntary recall."

Collins said the Curious George line accounts for about $6 million annually for a company that posts $350 million a year in revenue.

The notice the centre sent to New York-based Marvel is a required first step to filing a lawsuit under a California law that requires companies to post warnings about cancer-causing chemicals or reproductive toxins on their products.

The centre sent a similar notice Wednesday to Chicago-based Sassafras Enterprises Inc. after it said it found a lunch box sold by the company containing too much lead.

Sassafras officials could not be reached for comment late Wednesday.

The centre's findings are only the latest in a string of product defects that have prompted several recalls of Chinese-made products.

Since August, Mattel has announced three separate recalls of some 21 million toys because of dangers to children from lead paint or from tiny magnets that can be harmful if swallowed.

The center is calling for tougher lead tests of toys before they are placed on store shelves, including a standardized test to be applied throughout the industry.

More than 70 major U.S. retailers agreed last year to stop selling children's jewelry containing lead in California after the center and the state's attorney general sued in 2004.

The centre said it has asked California Attorney General Jerry Brown to join its latest effort.

"It's a very serious issue, so we're going to look at their evidence and allegations very carefully and decide whether we'll file a lawsuit," Supervising Deputy Attorney General Ed Weil said Wednesday.