Los Angeles Angels superstar Shohei Ohtani and four-time Grand Slam winner Naomi Osaka were among high-profile celebrities who have been sued in a U.S. class action lawsuit this week over the collapse of major crypto exchange FTX.

The lawsuit filed in a federal district court in Florida alleges FTX' former CEO Sam Bankman-Fried and the celebrities, also including NFL quarterback Tom Brady and NBA superstar Stephen Curry, are liable for promoting the exchange and causing damages to investors.

Shohei Ohtani (L, Getty) and Naomi Osaka. (Kyodo)

While the total sum being sought by the plaintiffs is unclear, the complaint said "American consumers collectively sustained over $11 billion" in damages due to FTX. It also said the lawsuit "seeks to hold defendants responsible for the many billions of dollars" in losses they caused the plaintiffs.

Osaka and Ohtani both served as brand ambassadors of FTX, the complaint said.

FTX, founded in 2019, raised its profile by acquiring the naming rights for a professional basketball arena in the United States and by signing sponsorship deals with star athletes and getting them to appear in commercials for the exchange.

As one of the world's leading crypto exchanges, FTX's customers are thought to have numbered over 1 million.

But it filed for bankruptcy protection this month after facing a severe liquidity crisis. Bankman-Fried, who has been seen as the face of the cryptocurrency industry, resigned as CEO.