A senior official said that the U.S. Securities and Exchange Commission SEC was tightening the scrutiny of the work audit firms do for criptocurrencies companies.
Paul Munter, SEC's acting chief accountant, said investors should be very cautious about some of the claims that are being made by the companies.
The FTX collapsed across the industry, hobbling liquidity at firms with exposure to one of the world's biggest exchanges, and has prompted investigations by regulators in several countries.
FTX filed for U.S. bankruptcy protection last month and its founder Sam Bankman- Fried resigned as chief executive after rival exchange Binance walked away from a proposed acquisition.
Several firms have been bracing for a fallout from the FTX collapse, with many counting their exposure in millions to the beleaguered exchange.