More retailers remove magnetic putty over arsenic fears
The "Magnetic Putty" had seven times the permitted amount of the poison and was barred from sale by Northamptonshire Trading Standards.
Groupon and eBay have removed listings for the putty, following Amazon.
Ben Clark, 12, received it as a Christmas gift and his father, Jonny Clark, told the BBC he was "angry" at Amazon's "massive failure".
Amazon said if users had concerns they can contact their customer service.
Auction site eBay said the listings have been removed and anyone who had an item they are unhappy with should contact them immediately.
A Groupon spokesman said the product was no longer available on their website and an investigation with the supplier has begun.
He added: "We are speaking to customers to tell them to stop using the product immediately. It goes without saying customers will be refunded for their purchase."