The U.S. Securities and Exchange Commission (SEC) is investigating whether crypto exchange Binance Holdings Ltd's initial coin offering in 2017 broke the agency's rules, Bloomberg reported, citing people familiar with the matter.

SEC investigators are examining if the offering of BNB token amounted to the sale of a security that should have been registered with the agency, the report https://www.bloomberg.com/news/articles/2022-06-06/us-probes-binance-over-token-that-is-now-world-s-fifth-largest?sref=ZoyErlU1 said on Monday.

The investigation adds to the troubles for Binance, one of the world's largest crypto exchange, which is already plagued by legal issues and controversies.

Spokespersons for SEC and Binance did not immediately respond to Reuters requests for comments.