Singapore on Friday said it planned to regulate the sale of "blind box" products after the controversial marketing strategy raised concerns worldwide about gambling inducement.

Blind boxes are retail products, typically toys or collectibles, sold in sealed packaging that do not disclose their contents until after purchase.

Consumer advocates and policymakers have raised concerns that the scheme resembles gambling, particularly where buyers pay for a chance to get higher-value or rare items.

Home Affairs Minister K Shanmugam said in a written reply to a question in parliament that the city-state was considering legislation making it mandatory for the boxes to disclose the probability of receiving certain items.

"The regulations are being drafted," said Shanmugam, who is also the Coordinating Minister for National Security.

His fellow MPs' "suggestion to have mandatory and standardised odds and probability disclosure will be among the points that will be considered for the regulations," Shanmugam added.

Blind boxes have been popularised in physical toy stores and online marketplaces and have driven sales for toy makers such as China's Pop Mart, which has six outlets in Singapore, according to its website.

Digital variants, commonly referred to as "gacha" mechanics in online games and mobile apps, similarly involve randomised rewards.

While fans love it, regulators and critics increasingly view it as a predatory practice that blurs the line between shopping and gambling.

There is particular concern for minors, who are among the most vulnerable to the marketing scheme. (AFP)