An NFT is a type of crypto asset that allows you to own a digital asset such as an art photo, video, song or other asset that you can buy.
The Portuguese football legend launched his own collection of NFTs through Binance, the world's largest cryptocurrency exchange, in the run-up to the 2022 World Cup.
Ronaldo's collection of NFTs includes animated sculptures depicting special moments in his life.
Some rare items have sold for up to $10,<>, but affected customers claim his endorsement has prompted them to make costly and unsafe investments.
The lawsuit comes a week after Binance reached a $4 billion settlement with U.S. regulators, leading to the resignation of the platform's CEO.
Despite the controversy, Ronaldo decided to continue cooperating with the platform, and published on his official account an announcement of an upcoming partnership between them.
Chinese billionaire Zhao, the platform's owner and CEO, has pleaded guilty to violating anti-money laundering laws and could face jail time sentenced next year.
According to the lawsuit, Binance's NFT sales were driven by "help from some of the wealthiest and most powerful organizations and celebrities around the world," including Ronaldo.
According to Sky News, online searches for Binance rose by 500 percent after the announcement of Ronaldo's collection, and his non-fungible tokens were sold out within a week.
The court filings also allege that Ronaldo should have disclosed the amount he received for the high-profile partnership.