Vivid has said that the practise of opening Moshling blind bags to sell figures individually is illegal and poses a safety risk to young children.
Neil Bandtock, Vivid UK's managing director, said: "As soon as the blind-bag packaging is removed from the Moshlings collectables by retailers there is no small parts warning for the product and as a result younger siblings could be endangered."
He continued: "We have a legal duty to ensure our products are being retailed in a safe and acceptable manner and after consultation with our local Trading Standards Officer decided that we needed to issue this warning to prevent a potential tragedy.
"As long as retailers do not break-up blind bags there is no problem with small parts warnings being separated from product and we thank the 99.9 per cent of our customers who are behaving responsibly."
Moshi Monsters, the kids virtual world from Mind Candy, reached 50 million users this year. Early sales tracking in the UK, North America, Australia, New Zealand and South Africa suggests that the licensed toys from Vivid could be worth more than $200 million at retail in the coming 12 months.